Cov ntaub ntawv ob-seem, xws li graphene, yog qhov zoo rau ob qho tib si cov ntawv thov semiconductor ib txwm muaj thiab cov ntawv thov tshiab hauv cov khoom siv hluav taws xob yooj ywm. Txawm li cas los xij, lub zog tensile siab ntawm graphene ua rau muaj kev tawg ntawm qhov tsis tshua muaj zog, ua rau nws nyuaj rau siv nws cov khoom siv hluav taws xob zoo kawg nkaus hauv cov khoom siv hluav taws xob ncab tau. Txhawm rau kom ua tau zoo heev ntawm cov neeg ua haujlwm graphene pob tshab, peb tau tsim graphene nanoscrolls nyob nruab nrab ntawm cov khaubncaws sab nraud povtseg graphene, hu ua multilayer graphene / graphene scrolls (MGGs). Hauv qab kev ntxhov siab, qee cov scrolls txuas cov chaw sib cais ntawm graphene kom tswj tau lub network percolating uas ua rau muaj kev ua tau zoo heev ntawm cov kev ntxhov siab siab. Trilayer MGGs txhawb nqa ntawm elastomers khaws cia 65% ntawm lawv cov conductance thawj zaug ntawm 100% kev ntxhov siab, uas yog perpendicular rau qhov kev taw qhia ntawm cov dej ntws tam sim no, thaum cov yeeb yaj kiab trilayer ntawm graphene tsis muaj nanoscrolls khaws cia tsuas yog 25% ntawm lawv cov conductance pib. Ib lub transistor uas muaj cov pa roj carbon uas ncab tau uas siv MGGs ua electrodes tau qhia txog kev xa hluav taws xob ntawm >90% thiab khaws cia 60% ntawm nws cov zis tam sim no thaum muaj 120% kev ntxhov siab (ua ke nrog kev coj ntawm kev thauj mus los). Cov transistors uas muaj cov pa roj carbon uas ncab tau thiab pob tshab no tuaj yeem ua rau muaj cov optoelectronics uas ncab tau zoo heev.
Cov khoom siv hluav taws xob uas nthuav tau yog ib qho chaw loj hlob uas muaj cov ntawv thov tseem ceeb hauv cov txheej txheem biointegrated siab heev (1, 2) nrog rau lub peev xwm los koom ua ke nrog cov optoelectronics uas nthuav tau (3, 4) los tsim cov neeg hlau mos mos thiab cov zaub. Graphene qhia txog cov khoom zoo heev ntawm atomic thickness, siab transparency, thiab siab conductivity, tab sis nws txoj kev siv hauv cov ntawv thov uas nthuav tau raug txwv los ntawm nws txoj kev nyiam tawg ntawm cov kab me me. Kev kov yeej cov kev txwv ntawm graphene tuaj yeem ua rau muaj kev ua haujlwm tshiab hauv cov khoom siv uas nthuav tau.
Cov khoom tshwj xeeb ntawm graphene ua rau nws yog tus neeg sib tw muaj zog rau tiam tom ntej ntawm cov electrodes conductive pob tshab (5, 6). Piv nrog rau cov neeg hlau pob tshab feem ntau siv, indium tin oxide [ITO; 100 ohms / square (sq) ntawm 90% pob tshab], monolayer graphene loj hlob los ntawm cov tshuaj vapor deposition (CVD) muaj kev sib xyaw zoo sib xws ntawm daim ntawv tsis kam (125 ohms / sq) thiab pob tshab (97.4%) (5). Tsis tas li ntawd, cov yeeb yaj kiab graphene muaj kev ywj pheej tshwj xeeb piv rau ITO (7). Piv txwv li, ntawm cov yas substrate, nws cov conductance tuaj yeem khaws cia txawm tias rau qhov khoov vojvoog ntawm curvature me me li 0.8 hli (8). Txhawm rau txhim kho nws cov kev ua haujlwm hluav taws xob ua tus neeg hlau pob tshab yooj ywm, cov haujlwm yav dhau los tau tsim cov ntaub ntawv graphene hybrid nrog ib-dimensional (1D) silver nanowires lossis carbon nanotubes (CNTs) (9–11). Ntxiv mus, graphene tau siv ua electrodes rau cov khoom sib xyaw ua ke heterostructural semiconductors (xws li 2D bulk Si, 1D nanowires / nanotubes, thiab 0D quantum dots) (12), cov transistors yooj ywm, cov hlwb hnub ci, thiab cov teeb pom kev zoo (LEDs) (13–23).
Txawm hais tias graphene tau qhia txog cov txiaj ntsig zoo rau cov khoom siv hluav taws xob yooj ywm, nws daim ntawv thov hauv cov khoom siv hluav taws xob ncab tau raug txwv los ntawm nws cov khoom siv kho tshuab (17, 24, 25); graphene muaj qhov tawv nqaij hauv-dav hlau ntawm 340 N / m thiab Young's modulus ntawm 0.5 TPa (26). Lub network carbon-carbon muaj zog tsis muab cov txheej txheem dissipation zog rau kev siv zog thiab yog li ntawd yooj yim tawg ntawm tsawg dua 5% kev nyuaj siab. Piv txwv li, CVD graphene hloov mus rau polydimethylsiloxane (PDMS) elastic substrate tsuas yog tuaj yeem tswj nws cov conductivity ntawm tsawg dua 6% kev nyuaj siab (8). Kev suav theoretical qhia tau hais tias crumpling thiab interplay ntawm cov khaubncaws sab nraud povtseg sib txawv yuav tsum txo qhov tawv nqaij (26). Los ntawm kev sib sau ua ke graphene rau hauv ntau txheej, nws tau tshaj tawm tias qhov bi- lossis trilayer graphene no ncab tau mus rau 30% kev nyuaj siab, qhia txog kev hloov pauv tsis kam 13 zaug me dua li ntawm monolayer graphene (27). Txawm li cas los xij, qhov kev ncab no tseem qis dua li cov khoom siv ncab tau niaj hnub (28, 29).
Cov transistors tseem ceeb heev rau cov ntawv thov ncab tau vim tias lawv ua rau muaj kev nyeem ntawv sensor thiab kev tshuaj xyuas teeb liab (30, 31). Cov transistors ntawm PDMS nrog ntau txheej graphene ua cov electrodes qhov chaw / ntws thiab cov khoom siv channel tuaj yeem tswj hwm kev ua haujlwm hluav taws xob txog li 5% kev ntxhov siab (32), uas yog qis dua qhov tsawg kawg nkaus xav tau (~ 50%) rau cov sensors saib xyuas kev noj qab haus huv thiab daim tawv nqaij hluav taws xob (33, 34). Tsis ntev los no, txoj hauv kev graphene kirigami tau tshawb nrhiav, thiab cov transistor gated los ntawm cov kua electrolyte tuaj yeem ncab mus txog li 240% (35). Txawm li cas los xij, txoj kev no xav tau graphene ncua, uas ua rau cov txheej txheem tsim khoom nyuaj.
Ntawm no, peb ua tiav cov khoom siv graphene uas ncab tau zoo heev los ntawm kev sib xyaw cov graphene scrolls (~ 1 txog 20 μm ntev, ~ 0.1 txog 1 μm dav, thiab ~ 10 txog 100 nm siab) ntawm cov txheej graphene. Peb xav tias cov graphene scrolls no tuaj yeem muab cov kev coj ua rau cov kab nrib pleb hauv cov ntawv graphene, yog li tswj tau qhov kev coj ua siab nyob rau hauv kev ntxhov siab. Cov graphene scrolls tsis xav tau kev sib xyaw lossis cov txheej txheem ntxiv; lawv tau tsim ntuj tsim thaum lub sijhawm hloov pauv ntub. Los ntawm kev siv ntau txheej G / G (graphene / graphene) scrolls (MGGs) graphene stretchable electrodes (qhov chaw / ntws thiab rooj vag) thiab semiconducting CNTs, peb tau ua pov thawj pom tseeb thiab ncab tau tag nrho cov carbon transistors, uas tuaj yeem ncab mus rau 120% kev ntxhov siab (sib npaug rau kev coj ntawm kev thauj mus los) thiab khaws cia 60% ntawm lawv cov zis tam sim no. Qhov no yog cov transistor carbon-raws li pob tshab tshaj plaws kom deb li deb, thiab nws muab tam sim no txaus los tsav lub LED inorganic.
Yuav kom ua tau cov electrodes graphene uas nthuav tau hauv thaj chaw loj, peb tau xaiv graphene uas loj hlob ntawm CVD rau ntawm Cu foil. Cu foil tau dai rau hauv nruab nrab ntawm lub raj CVD quartz kom tso cai rau kev loj hlob ntawm graphene ntawm ob sab, tsim cov qauv G/Cu/G. Txhawm rau hloov graphene, peb thawj zaug tig-coated ib txheej nyias ntawm poly(methyl methacrylate) (PMMA) los tiv thaiv ib sab ntawm graphene, uas peb hu ua topside graphene (vice versa rau sab tod ntawm graphene), thiab tom qab ntawd, tag nrho zaj duab xis (PMMA/sab saum toj graphene/Cu/hauv qab graphene) tau ntub rau hauv (NH4)2S2O8 kua kom tshem tawm Cu foil. Lub graphene hauv qab tsis muaj PMMA txheej yuav tsis zam tau muaj cov kab nrib pleb thiab qhov tsis zoo uas tso cai rau etchant nkag mus rau hauv (36, 37). Raws li tau piav qhia hauv daim duab 1A, nyob rau hauv qhov cuam tshuam ntawm qhov nro ntawm qhov chaw, cov graphene domains tso tawm dov rau hauv cov ntawv thiab tom qab ntawd txuas rau ntawm zaj duab xis sab saum toj-G/PMMA seem. Cov ntawv scrolls sab saum toj-G/G tuaj yeem hloov mus rau txhua lub substrate, xws li SiO2/Si, iav, lossis polymer mos. Rov ua qhov txheej txheem hloov pauv no ntau zaus rau tib lub substrate muab cov qauv MGG.
(A) Daim duab kos ntawm cov txheej txheem tsim khoom rau MGGs ua lub electrode ncab tau. Thaum lub sijhawm hloov graphene, backside graphene ntawm Cu ntawv ci tau tawg ntawm cov ciam teb thiab qhov tsis zoo, dov mus rau hauv cov duab tsis zoo, thiab nruj nreem txuas rau ntawm cov yeeb yaj kiab sab saud, tsim cov nanoscrolls. Daim duab kos thib plaub qhia txog cov qauv MGG uas tau teeb tsa. (B thiab C) Cov yam ntxwv TEM siab daws teeb meem ntawm monolayer MGG, tsom mus rau monolayer graphene (B) thiab thaj chaw scroll (C), feem. Lub inset ntawm (B) yog daim duab qis-magnification qhia txog tag nrho cov morphology ntawm monolayer MGGs ntawm TEM grid. Insets ntawm (C) yog cov profiles muaj zog coj raws cov thawv rectangular qhia hauv daim duab, qhov twg qhov deb ntawm cov dav hlau atomic yog 0.34 thiab 0.41 nm. (D) Carbon K-edge EEL spectrum nrog cov yam ntxwv graphitic π * thiab σ * peaks labeled. (E) Daim duab AFM seem ntawm monolayer G / G scrolls nrog qhov siab profile raws kab daj dotted. (F txog I) Lub tshuab tsom iav pom kev thiab daim duab AFM ntawm peb txheej G tsis muaj (F thiab H) thiab nrog cov scrolls (G thiab I) ntawm 300-nm-tuab SiO2/Si substrates, raws li. Cov scrolls thiab wrinkles sawv cev tau muab cim los qhia lawv qhov sib txawv.
Yuav kom paub tseeb tias cov scrolls yog dov graphene hauv xwm, peb tau ua qhov kev tshawb fawb high-resolution transmission electron microscopy (TEM) thiab electron energy loss (EEL) spectroscopy ntawm monolayer top-G/G scroll structures. Daim duab 1B qhia txog cov qauv hexagonal ntawm monolayer graphene, thiab qhov inset yog qhov morphology tag nrho ntawm zaj duab xis uas npog rau ntawm ib lub qhov carbon ntawm TEM grid. Lub monolayer graphene spans feem ntau ntawm lub grid, thiab qee cov graphene flakes nyob rau hauv qhov muaj ntau lub stacks ntawm hexagonal rings tshwm sim (Daim duab 1B). Los ntawm kev zooming rau hauv ib tus kheej scroll (Daim duab 1C), peb tau pom ntau ntawm graphene lattice fringes, nrog rau qhov lattice spacing nyob rau hauv ntau ntawm 0.34 txog 0.41 nm. Cov kev ntsuas no qhia tau hais tias cov flakes raug dov random thiab tsis yog graphite zoo meej, uas muaj qhov lattice spacing ntawm 0.34 nm hauv "ABAB" txheej stacking. Daim Duab 1D qhia txog cov pa roj carbon K-edge EEL spectrum, qhov twg lub ncov ntawm 285 eV pib los ntawm π * orbital thiab lwm qhov nyob ib puag ncig 290 eV yog vim muaj kev hloov pauv ntawm σ * orbital. Nws tuaj yeem pom tias sp2 bonding dominates hauv cov qauv no, pov thawj tias cov scrolls yog graphitic heev.
Cov duab ntawm lub tshuab tsom iav thiab cov duab ntawm lub zog atomic microscopy (AFM) muab kev nkag siab txog kev faib tawm ntawm graphene nanoscrolls hauv MGGs (Daim Duab 1, E txog G, thiab daim duab S1 thiab S2). Cov scrolls raug faib tsis raws cai hla qhov chaw, thiab lawv qhov ceev hauv-dav hlau nce ntxiv raws li tus lej ntawm cov txheej sib dhos. Ntau cov scrolls raug sib xyaw ua ke thiab qhia txog qhov siab tsis sib xws hauv qhov ntau ntawm 10 txog 100 nm. Lawv yog 1 txog 20 μm ntev thiab 0.1 txog 1 μm dav, nyob ntawm qhov loj ntawm lawv cov graphene flakes pib. Raws li pom hauv Daim Duab 1 (H thiab I), cov scrolls muaj qhov loj dua li cov wrinkles, ua rau muaj qhov sib txuas ntau dua ntawm cov txheej graphene.
Txhawm rau ntsuas cov khoom siv hluav taws xob, peb tau tsim cov yeeb yaj kiab graphene nrog lossis tsis muaj cov qauv scroll thiab txheej stacking rau hauv 300-μm-dav thiab 2000-μm-ntev strips siv photolithography. Ob-probe resistances ua haujlwm ntawm kev ntxhov siab tau ntsuas nyob rau hauv cov xwm txheej ambient. Qhov muaj cov scrolls txo qhov resistivity rau monolayer graphene los ntawm 80% nrog tsuas yog 2.2% txo qis hauv transmittance (daim duab S4). Qhov no lees paub tias nanoscrolls, uas muaj qhov ceev tam sim no siab txog li 5 × 107 A / cm2 (38, 39), ua rau muaj kev pab hluav taws xob zoo heev rau MGGs. Ntawm tag nrho cov mono-, bi-, thiab trilayer tiaj tus graphene thiab MGGs, trilayer MGG muaj qhov conductance zoo tshaj plaws nrog kev pom tseeb ntawm yuav luag 90%. Txhawm rau piv rau lwm qhov chaw ntawm graphene tau tshaj tawm hauv cov ntaub ntawv, peb kuj ntsuas plaub-probe daim ntawv tiv thaiv (daim duab S5) thiab teev lawv ua haujlwm ntawm kev xa tawm ntawm 550 nm (daim duab S6) hauv daim duab 2A. MGG qhia tau tias muaj kev sib piv lossis siab dua conductivity thiab pob tshab dua li artificially stacked multilayer yer plain graphene thiab txo graphene oxide (RGO) (6, 8, 18). Nco ntsoov tias cov ntawv tiv thaiv ntawm artificially stacked multilayer plain graphene los ntawm cov ntaub ntawv yog me ntsis siab dua li ntawm peb MGG, tej zaum vim lawv cov xwm txheej kev loj hlob tsis zoo thiab txoj kev hloov pauv.
(A) Plaub-probe daim ntawv tiv thaiv piv rau kev xa tawm ntawm 550 nm rau ntau hom graphene, qhov twg cov plaub fab dub qhia txog mono-, bi-, thiab trilayer MGGs; cov voj voog liab thiab cov duab peb ceg xiav sib raug nrog ntau txheej graphene dawb loj hlob ntawm Cu thiab Ni los ntawm kev tshawb fawb ntawm Li et al. (6) thiab Kim et al. (8), feem, thiab tom qab ntawd hloov mus rau SiO2 / Si lossis quartz; thiab cov duab peb ceg ntsuab yog cov nqi rau RGO ntawm ntau qib txo qis los ntawm kev tshawb fawb ntawm Bonaccorso et al. (18). (B thiab C) Kev hloov pauv tsis tu ncua ntawm mono-, bi- thiab trilayer MGGs thiab G ua haujlwm ntawm perpendicular (B) thiab parallel (C) kev ntxhov siab rau qhov kev taw qhia ntawm cov dej ntws tam sim no. (D) Kev hloov pauv tsis tu ncua ntawm bilayer G (liab) thiab MGG (dub) nyob rau hauv cyclic strain loading txog li 50% perpendicular strain. (E) Kev hloov pauv tsis tu ncua ntawm trilayer G (liab) thiab MGG (dub) nyob rau hauv cyclic strain loading txog li 90% parallel strain. (F) Kev hloov pauv capacitance ntawm mono-, bi- thiab trilayer G thiab bi- thiab trilayer MGGs ua lub luag haujlwm ntawm kev ntxhov siab. Qhov ntxig yog cov qauv capacitor, qhov twg cov polymer substrate yog SEBS thiab cov polymer dielectric txheej yog 2-μm-tuab SEBS.
Txhawm rau soj ntsuam qhov kev ua tau zoo ntawm MGG, peb tau hloov graphene mus rau ntawm thermoplastic elastomer styrene-ethylene-butadiene-styrene (SEBS) substrates (~ 2 cm dav thiab ~ 5 cm ntev), thiab qhov conductivity tau ntsuas thaum lub substrate tau ncab (saib Cov Khoom Siv thiab Cov Txheej Txheem) ob qho tib si perpendicular thiab sib luag rau qhov kev taw qhia ntawm cov dej ntws tam sim no (Daim Duab 2, B thiab C). Tus cwj pwm hluav taws xob uas nyob ntawm cov dej ntws tau zoo dua nrog kev koom ua ke ntawm nanoscrolls thiab nce tus lej ntawm graphene txheej. Piv txwv li, thaum cov dej ntws yog perpendicular rau cov dej ntws tam sim no, rau monolayer graphene, qhov ntxiv ntawm scrolls ua rau cov dej ntws ntawm cov hluav taws xob tawg ntawm 5 txog 70%. Qhov kev kam rau siab ntawm trilayer graphene kuj tau txhim kho zoo dua piv rau monolayer graphene. Nrog nanoscrolls, ntawm 100% perpendicular strain, qhov kev tiv thaiv ntawm trilayer MGG qauv tsuas yog nce 50%, piv rau 300% rau trilayer graphene tsis muaj scrolls. Kev hloov pauv tiv thaiv nyob rau hauv cyclic strain load ing tau tshawb xyuas. Piv txwv li (Daim Duab 2D), qhov kev tiv thaiv ntawm cov yeeb yaj kiab graphene bilayer yooj yim nce txog 7.5 zaug tom qab ~ 700 lub voj voog ntawm 50% perpendicular strain thiab khaws cia nce nrog kev ntxhov siab hauv txhua lub voj voog. Ntawm qhov tod tes, qhov kev tiv thaiv ntawm bilayer MGG tsuas yog nce txog 2.5 zaug tom qab ~ 700 lub voj voog. Siv txog li 90% kev ntxhov siab raws li kev coj ua sib luag, qhov kev tiv thaiv ntawm trilayer graphene nce ~ 100 zaug tom qab 1000 lub voj voog, thaum nws tsuas yog ~ 8 zaug hauv trilayer MGG (Daim Duab 2E). Cov txiaj ntsig kev voj voog tau qhia hauv daim duab S7. Qhov kev nce ntxiv sai dua hauv kev tiv thaiv raws li kev coj ua sib luag yog vim qhov kev taw qhia ntawm cov kab nrib pleb yog perpendicular rau qhov kev taw qhia ntawm cov dej ntws tam sim no. Qhov kev hloov pauv ntawm kev tiv thaiv thaum lub sijhawm thauj khoom thiab tshem tawm kev ntxhov siab yog vim qhov rov qab los ntawm viscoelastic ntawm SEBS elastomer substrate. Qhov kev tiv thaiv ruaj khov ntawm MGG strips thaum lub sijhawm voj voog yog vim muaj cov scrolls loj uas tuaj yeem txuas cov qhov tawg ntawm graphene (raws li pom los ntawm AFM), pab tswj txoj hauv kev percolating. Qhov xwm txheej no ntawm kev tswj hwm kev coj ua los ntawm txoj kev percolating tau tshaj tawm ua ntej rau cov hlau tawg lossis cov yeeb yaj kiab semiconductor ntawm elastomer substrates (40, 41).
Txhawm rau soj ntsuam cov yeeb yaj kiab graphene-based no ua cov electrodes rooj vag hauv cov khoom siv ncab tau, peb tau npog cov txheej graphene nrog SEBS dielectric txheej (2 μm tuab) thiab saib xyuas qhov kev hloov pauv dielectric capacitance ua haujlwm ntawm kev ntxhov siab (saib daim duab 2F thiab Cov Khoom Siv Ntxiv rau cov ntsiab lus). Peb tau pom tias capacitances nrog cov monolayer thiab bilayer graphene electrodes tau txo qis sai vim yog qhov poob ntawm kev coj ua hauv-dav hlau ntawm graphene. Hauv kev sib piv, capacitances gated los ntawm MGGs nrog rau cov trilayer graphene dawb tau qhia txog kev nce ntawm capacitance nrog kev ntxhov siab, uas xav tau vim yog kev txo qis hauv dielectric thickness nrog kev ntxhov siab. Qhov kev cia siab nce hauv capacitance phim zoo heev nrog MGG qauv (daim duab S8). Qhov no qhia tau hais tias MGG yog qhov tsim nyog ua lub rooj vag electrode rau cov transistors ncab tau.
Txhawm rau tshawb nrhiav ntxiv txog lub luag haujlwm ntawm 1D graphene scroll ntawm kev kam rau siab ntawm kev ua hluav taws xob thiab tswj hwm qhov kev sib cais ntawm cov txheej graphene zoo dua, peb siv cov tshuaj tsuag-coated CNTs los hloov cov graphene scrolls (saib Cov Khoom Siv Ntxiv). Txhawm rau ua raws li cov qauv MGG, peb tau tso peb qhov ceev ntawm CNTs (uas yog, CNT1
(A txog C) cov duab AFM ntawm peb qhov sib txawv ntawm CNTs (CNT1)
Yuav kom nkag siab ntxiv txog lawv lub peev xwm ua cov electrodes rau cov khoom siv hluav taws xob ncab tau, peb tau tshawb xyuas cov morphologies ntawm MGG thiab G-CNT-G nyob rau hauv kev ntxhov siab. Optical microscopy thiab scanning electron microscopy (SEM) tsis yog cov txheej txheem piav qhia zoo vim tias ob qho tib si tsis muaj xim sib piv thiab SEM raug rau cov duab artifacts thaum lub sijhawm electron scanning thaum graphene nyob rau ntawm polymer substrates (figs. S9 thiab S10). Txhawm rau saib xyuas qhov chaw graphene nyob rau hauv kev ntxhov siab, peb tau sau cov kev ntsuas AFM ntawm trilayer MGGs thiab graphene dawb tom qab hloov mus rau nyias heev (~ 0.1 hli tuab) thiab elastic SEBS substrates. Vim yog qhov tsis zoo intrinsic hauv CVD graphene thiab kev puas tsuaj sab nraud thaum lub sijhawm hloov pauv, cov kab nrib pleb yog inevitably tsim rau ntawm graphene strained, thiab nrog kev ntxhov siab ntxiv, cov kab nrib pleb tau dhau los ua denser (Daim duab 4, A txog D). Nyob ntawm cov qauv stacking ntawm cov electrodes carbon-based, cov kab nrib pleb qhia txog cov morphologies sib txawv (daim duab S11) (27). Qhov ceev ntawm thaj chaw tawg (txhais tau tias yog thaj chaw tawg/cheeb tsam uas tau soj ntsuam) ntawm ntau txheej graphene yog tsawg dua li ntawm monolayer graphene tom qab kev ntxhov siab, uas yog sib xws nrog kev nce ntxiv ntawm kev coj hluav taws xob rau MGGs. Ntawm qhov tod tes, cov scrolls feem ntau pom los txuas cov kab nrib pleb, muab cov kev coj hluav taws xob ntxiv hauv zaj duab xis uas raug ntxhov siab. Piv txwv li, raws li tau sau tseg hauv daim duab ntawm Daim Duab 4B, ib daim scroll dav dav hla ib qho kab nrib pleb hauv trilayer MGG, tab sis tsis muaj scroll tau pom hauv graphene tiaj tus (Daim Duab 4, E rau H). Ib yam li ntawd, CNTs kuj txuas cov kab nrib pleb hauv graphene (daim duab S11). Qhov ceev ntawm thaj chaw tawg, qhov ceev ntawm thaj chaw scroll, thiab qhov roughness ntawm cov zaj duab xis tau muab tso ua ke hauv Daim Duab 4K.
(A txog H) Cov duab AFM hauv situ ntawm trilayer G/G scrolls (A txog D) thiab trilayer G qauv (E txog H) ntawm SEBS nyias heev (~ 0.1 hli tuab) elastomer ntawm 0, 20, 60, thiab 100% kev ntxhov siab. Cov kab nrib pleb thiab scrolls sawv cev tau taw qhia nrog xub. Tag nrho cov duab AFM nyob hauv thaj tsam ntawm 15 μm × 15 μm, siv tib lub teeb xim raws li tau sau tseg. (I) Kev sim geometry ntawm cov qauv monolayer graphene electrodes ntawm SEBS substrate. (J) Daim ntawv qhia contour simulation ntawm qhov siab tshaj plaws tseem ceeb logarithmic kev ntxhov siab hauv monolayer graphene thiab SEBS substrate ntawm 20% kev ntxhov siab sab nraud. (K) Kev sib piv ntawm qhov ceev ntawm thaj chaw tawg (kab liab), qhov ceev ntawm thaj chaw scroll (kab daj), thiab qhov roughness ntawm qhov chaw (kab xiav) rau cov qauv graphene sib txawv.
Thaum cov yeeb yaj kiab MGG raug ncab, muaj ib qho tseem ceeb ntxiv uas cov scrolls tuaj yeem txuas cov cheeb tsam tawg ntawm graphene, tswj hwm lub network percolating. Cov graphene scrolls muaj kev cia siab vim tias lawv tuaj yeem ntev txog kaum micrometers thiab yog li ntawd tuaj yeem txuas cov kab nrib pleb uas feem ntau mus txog micrometer scale. Ntxiv mus, vim tias cov scrolls muaj ntau txheej ntawm graphene, lawv xav tias yuav muaj kev tiv thaiv qis. Piv txwv li, cov CNT networks uas ntom ntom (qis dua transmittance) yuav tsum muaj peev xwm sib piv conductive bridging, vim CNTs me dua (feem ntau yog ob peb micrometers ntev) thiab tsis conductive dua li scrolls. Ntawm qhov tod tes, raws li pom hauv daim duab S12, thaum graphene tawg thaum lub sijhawm ncab kom haum rau kev ntxhov siab, cov scrolls tsis tawg, qhia tias qhov kawg yuav swb rau ntawm graphene hauv qab. Qhov laj thawj uas lawv tsis tawg tej zaum yog vim cov qauv dov, uas muaj ntau txheej ntawm graphene (~ 1 txog 2 0 μm ntev, ~ 0.1 txog 1 μm dav, thiab ~ 10 txog 100 nm siab), uas muaj cov modulus zoo dua li cov graphene ib txheej. Raws li tau tshaj tawm los ntawm Green thiab Hersam (42), cov hlau CNT tes hauj lwm (lub raj txoj kab uas hla ntawm 1.0 nm) tuaj yeem ua tiav cov ntawv tsis kam qis <100 ohms / sq txawm tias muaj kev sib txuas loj ntawm CNTs. Xav txog tias peb cov graphene scrolls muaj qhov dav ntawm 0.1 txog 1 μm thiab tias G / G scrolls muaj thaj chaw sib cuag loj dua li CNTs, qhov kev tiv tauj sib cuag thiab thaj chaw sib cuag ntawm graphene thiab graphene scrolls yuav tsum tsis yog cov yam txwv kom tswj tau qhov conductivity siab.
Cov graphene muaj cov modulus siab dua li SEBS substrate. Txawm hais tias qhov tuab ntawm cov graphene electrode qis dua li ntawm cov substrate, qhov tawv ntawm graphene zaug nws cov tuab yog sib piv rau cov substrate (43, 44), ua rau muaj qhov cuam tshuam nruab nrab ntawm cov kob tawv. Peb tau simulate qhov deformation ntawm 1-nm-tuab graphene ntawm SEBS substrate (saib Cov Khoom Siv Ntxiv rau cov ntsiab lus). Raws li cov txiaj ntsig simulation, thaum 20% kev nyuaj siab siv rau SEBS substrate sab nraud, qhov nruab nrab kev nyuaj siab hauv graphene yog ~ 6.6% (Daim duab 4J thiab daim duab S13D), uas yog sib xws nrog kev soj ntsuam sim (saib daim duab S13). Peb piv qhov kev nyuaj siab hauv cov qauv graphene thiab cov substrate thaj chaw siv lub tshuab microscopy thiab pom tias qhov kev nyuaj siab hauv thaj chaw substrate yuav tsum tsawg kawg yog ob npaug ntawm qhov kev nyuaj siab hauv thaj chaw graphene. Qhov no qhia tau hais tias qhov kev nyuaj siab siv rau ntawm cov qauv electrode graphene tuaj yeem raug txwv tsis pub dhau, tsim cov kob tawv graphene saum SEBS (26, 43, 44).
Yog li ntawd, lub peev xwm ntawm MGG electrodes kom tswj tau qhov conductivity siab nyob rau hauv qhov siab siab yuav ua tau los ntawm ob lub tshuab tseem ceeb: (i) Cov scrolls tuaj yeem txuas cov cheeb tsam tsis sib txuas kom tswj tau txoj kev percolation conductive, thiab (ii) cov ntawv graphene ntau txheej / elastomer yuav swb hla ib leeg, ua rau txo qis kev ntxhov siab ntawm graphene electrodes. Rau ntau txheej ntawm graphene hloov pauv ntawm elastomer, cov txheej tsis txuas nrog ib leeg, uas yuav swb teb rau kev ntxhov siab (27). Cov scrolls kuj tseem ua rau qhov roughness ntawm cov txheej graphene, uas yuav pab ua kom muaj kev sib cais ntawm cov txheej graphene thiab yog li ua rau muaj kev swb ntawm cov txheej graphene.
Cov khoom siv carbon tag nrho raug nrhiav kev kub siab vim tias tus nqi qis thiab kev ua haujlwm siab. Hauv peb qhov xwm txheej, cov transistors carbon tag nrho tau tsim los ntawm kev siv lub rooj vag graphene hauv qab, qhov chaw graphene sab saum toj / qhov dej ntws, lub semiconductor CNT uas tau txheeb xyuas, thiab SEBS ua dielectric (Daim Duab 5A). Raws li pom hauv Daim Duab 5B, cov khoom siv carbon tag nrho nrog CNTs ua qhov chaw / qhov dej ntws thiab rooj vag (lub cuab yeej hauv qab) yog qhov tsis pom tseeb dua li cov khoom siv nrog graphene electrodes (lub cuab yeej sab saum toj). Qhov no yog vim tias CNT network xav tau cov tuab dua thiab, yog li ntawd, qis dua optical transmittances kom ua tiav cov ntawv tsis kam zoo ib yam li graphene (daim duab S4). Daim Duab 5 (C thiab D) qhia cov sawv cev hloov pauv thiab cov kab tso zis ua ntej kev ntxhov siab rau lub transistor ua nrog bilayer MGG electrodes. Qhov dav thiab ntev ntawm cov channel transistor unstrained yog 800 thiab 100 μm, feem. Qhov ntsuas ntawm / tawm piv yog ntau dua 103 nrog rau thiab tawm tam sim no ntawm qib ntawm 10−5 thiab 10−8 A, feem. Cov kab nkhaus tso zis qhia txog cov kab ncaj thiab cov txheej txheem saturation zoo tagnrho nrog kev vam khom ntawm lub rooj vag-voltage, qhia txog kev sib cuag zoo tagnrho ntawm CNTs thiab graphene electrodes (45). Qhov kev tiv tauj tsis kam nrog graphene electrodes tau pom tias qis dua li qhov nrog cov zaj duab xis Au evaporated (saib daim duab S14). Qhov kev txav mus los ntawm cov transistor ncab tau yog li 5.6 cm2 / Vs, zoo ib yam li cov polymer-sorted CNT transistors tib yam ntawm cov khoom siv Si rigid nrog 300-nm SiO2 ua ib txheej dielectric. Kev txhim kho ntxiv hauv kev txav mus los yog ua tau nrog cov raj ceev ceev thiab lwm hom raj (46).
(A) Daim duab ntawm graphene-based stretchable transistor. SWNTs, ib phab ntsa carbon nanotubes. (B) Duab ntawm cov stretchable transistors ua los ntawm graphene electrodes (sab saum toj) thiab CNT electrodes (hauv qab). Qhov sib txawv ntawm kev pom tseeb yog pom tseeb. (C thiab D) Cov kab hloov pauv thiab cov zis ntawm graphene-based transistor ntawm SEBS ua ntej strain. (E thiab F) Cov kab hloov pauv, on thiab off tam sim no, on/off piv, thiab kev txav mus los ntawm graphene-based transistor ntawm ntau hom strains.
Thaum lub cuab yeej pob tshab, tag nrho cov pa roj carbon tau ncab mus rau hauv qhov kev taw qhia sib luag rau qhov kev thauj mus los, qhov kev puas tsuaj tsawg kawg nkaus tau pom txog li 120% kev ntxhov siab. Thaum lub sijhawm ncab, qhov kev txav mus los tau txo qis los ntawm 5.6 cm2 / Vs ntawm 0% kev ntxhov siab rau 2.5 cm2 / Vs ntawm 120% kev ntxhov siab (Daim duab 5F). Peb kuj tau piv rau qhov kev ua tau zoo ntawm transistor rau ntau qhov ntev ntawm cov channel (saib lub rooj S1). Qhov tseem ceeb, ntawm qhov kev ntxhov siab loj li 105%, tag nrho cov transistors no tseem tau qhia txog qhov siab ntawm / tawm piv (> 103) thiab kev txav mus los (> 3 cm2 / Vs). Tsis tas li ntawd, peb tau sau tag nrho cov haujlwm tsis ntev los no ntawm tag nrho cov pa roj carbon transistors (saib lub rooj S2) (47–52). Los ntawm kev ua kom zoo dua ntawm cov khoom siv tsim khoom ntawm elastomers thiab siv MGGs ua kev sib cuag, peb cov transistors tag nrho cov pa roj carbon qhia txog kev ua tau zoo hauv kev txav mus los thiab hysteresis nrog rau kev ncab tau zoo heev.
Ua ib daim ntawv thov ntawm lub transistor uas pob tshab thiab ncab tau, peb siv nws los tswj lub LED qhov kev hloov (Daim Duab 6A). Raws li pom hauv Daim Duab 6B, lub LED ntsuab tuaj yeem pom tseeb los ntawm lub cuab yeej ncab tau tag nrho-carbon uas muab tso rau saum toj. Thaum ncab mus txog ~ 100% (Daim Duab 6, C thiab D), lub zog ntawm lub teeb LED tsis hloov pauv, uas yog sib xws nrog kev ua tau zoo ntawm transistor piav qhia saum toj no (saib zaj yeeb yaj kiab S1). Qhov no yog thawj daim ntawv tshaj tawm ntawm cov chav tswj kev ncab tau ua los ntawm kev siv graphene electrodes, qhia txog qhov ua tau tshiab rau cov khoom siv hluav taws xob ncab tau graphene.
(A) Lub voj voog ntawm lub transistor los tsav LED. GND, av. (B) Duab ntawm lub transistor uas ncab tau thiab pob tshab tag nrho-carbon ntawm 0% strain mounted saum toj no lub LED ntsuab. (C) Lub transistor uas muaj tag nrho-carbon pob tshab thiab stretchable siv los hloov lub LED raug mounted saum toj no lub LED ntawm 0% (sab laug) thiab ~ 100% strain (sab xis). Cov xub dawb taw tes ua cov cim daj ntawm lub cuab yeej los qhia qhov kev hloov pauv deb uas raug ncab. (D) Sab pom ntawm lub transistor ncab, nrog rau lub LED thawb rau hauv elastomer.
Xaus lus, peb tau tsim ib lub qauv graphene uas muaj kev coj ua tau zoo uas tswj tau qhov kev coj ua tau zoo hauv qab cov kab mob loj xws li cov electrodes uas ncab tau, uas tau ua los ntawm graphene nanoscrolls nyob nruab nrab ntawm cov txheej graphene uas tau teeb tsa. Cov qauv electrode MGG bi- thiab trilayer no ntawm elastomer tuaj yeem tswj tau 21 thiab 65%, feem, ntawm lawv cov kev coj ua 0% ntawm qhov kev coj ua tau zoo ntawm qhov kev coj ua tau zoo txog li 100%, piv rau qhov poob tag nrho ntawm kev coj ua tau zoo ntawm 5% kev coj ua rau cov electrodes graphene monolayer. Cov kev coj ua ntxiv ntawm graphene scrolls nrog rau kev sib cuam tshuam tsis muaj zog ntawm cov txheej hloov pauv pab txhawb rau qhov kev coj ua tau zoo dua hauv qab kev coj ua. Peb tau siv cov qauv graphene no ntxiv los tsim cov transistors uas ncab tau tag nrho. Txog tam sim no, qhov no yog cov transistor uas ncab tau zoo tshaj plaws uas muaj kev pom tseeb zoo tshaj plaws yam tsis tas siv buckling. Txawm hais tias kev tshawb fawb tam sim no tau ua los pab kom graphene rau cov khoom siv hluav taws xob uas ncab tau, peb ntseeg tias txoj hauv kev no tuaj yeem nthuav dav mus rau lwm cov ntaub ntawv 2D kom ua rau cov khoom siv hluav taws xob 2D uas ncab tau.
Cov graphene CVD loj hauv thaj chaw tau loj hlob ntawm cov ntawv ci Cu uas raug ncua (99.999%; Alfa Aesar) nyob rau hauv qhov siab tas li ntawm 0.5 mtorr nrog 50-SCCM (tus qauv cubic centimeter ib feeb) CH4 thiab 20-SCCM H2 ua cov khoom ua ntej ntawm 1000 ° C. Ob sab ntawm cov ntawv ci Cu tau npog los ntawm monolayer graphene. Ib txheej nyias ntawm PMMA (2000 rpm; A4, Microchem) tau raug txheej rau ntawm ib sab ntawm cov ntawv ci Cu, tsim cov qauv PMMA / G / Cu ntawv ci / G. tom qab ntawd, tag nrho cov yeeb yaj kiab tau ntub rau hauv 0.1 M ammonium persulfate [(NH4) 2S2O8] kua rau li 2 teev kom tshem tawm cov ntawv ci Cu. Thaum lub sijhawm no, cov graphene sab nraub qaum tsis muaj kev tiv thaiv thawj zaug rhuav tshem raws cov ciam teb ntawm cov noob thiab tom qab ntawd dov rau hauv cov ntawv vim yog qhov nro ntawm qhov chaw. Cov ntawv tau txuas rau ntawm PMMA-txhawb nqa cov yeeb yaj kiab graphene sab saud, tsim cov ntawv PMMA / G / G. Cov yeeb yaj kiab tau ntxuav hauv dej deionized ntau zaus thiab muab tso rau ntawm lub substrate, xws li SiO2/Si lossis yas substrate. Thaum cov yeeb yaj kiab txuas nrog qhuav rau ntawm lub substrate, cov qauv tau raug tsau rau hauv acetone, 1:1 acetone/IPA (isopropyl cawv), thiab IPA rau 30 vib nas this kom tshem tawm PMMA. Cov yeeb yaj kiab tau raug cua sov ntawm 100°C rau 15 feeb lossis khaws cia rau hauv lub tshuab nqus tsev ib hmos kom tshem tawm cov dej uas raug ntes ua ntej lwm txheej ntawm G/G scroll tau hloov mus rau nws. Cov kauj ruam no yog kom tsis txhob muaj kev sib cais ntawm cov yeeb yaj kiab graphene ntawm lub substrate thiab xyuas kom meej tias muaj kev npog tag nrho ntawm MGGs thaum lub sijhawm tso tawm ntawm PMMA carrier txheej.
Cov qauv MGG tau pom siv lub tshuab tsom iav pom kev (Leica) thiab lub tshuab tsom iav hluav taws xob luam theej duab (1 kV; FEI). Lub tshuab tsom iav atomic force (Nanoscope III, Digital Instrument) tau ua haujlwm hauv hom tapping los saib cov ntsiab lus ntawm G scrolls. Kev pom tseeb ntawm zaj duab xis tau sim los ntawm lub tshuab spectrometer ultraviolet-pom tau (Agilent Cary 6000i). Rau kev sim thaum lub zog nyob raws qhov kev taw qhia ntawm cov dej ntws tam sim no, photolithography thiab O2 plasma tau siv los ua qauv graphene qauv rau hauv cov strips (~ 300 μm dav thiab ~ 2000 μm ntev), thiab Au (50 nm) electrodes tau tso rau hauv thermally siv cov ntsej muag ntxoov ntxoo ntawm ob qho kawg ntawm sab ntev. Cov graphene strips ces tau muab tso rau hauv kev sib cuag nrog SEBS elastomer (~ 2 cm dav thiab ~ 5 cm ntev), nrog rau qhov ntev ntawm cov strips sib luag rau sab luv ntawm SEBS ua raws li BOE (buffered oxide etch) (HF: H2O 1: 6) etching thiab eutectic gallium indium (EGaIn) ua hluav taws xob sib cuag. Rau kev sim sib luag, cov qauv graphene tsis muaj qauv (~ 5 × 10 hli) tau raug xa mus rau SEBS substrates, nrog cov axes ntev sib luag rau sab ntev ntawm SEBS substrate. Rau ob qho tib si, tag nrho G (tsis muaj G scrolls) / SEBS tau ncab raws sab ntev ntawm elastomer hauv lub cuab yeej siv tes, thiab hauv qhov chaw, peb ntsuas lawv cov kev hloov pauv tsis kam hauv qab kev ntxhov siab ntawm qhov chaw soj ntsuam nrog lub semiconductor analyzer (Keithley 4200-SCS).
Cov transistors uas ncab tau zoo thiab pob tshab tag nrho cov pa roj carbon ntawm cov substrate elastic tau tsim los ntawm cov txheej txheem hauv qab no kom tsis txhob muaj kev puas tsuaj rau cov organic solvent ntawm cov polymer dielectric thiab substrate. Cov qauv MGG tau hloov mus rau SEBS ua cov electrodes rooj vag. Txhawm rau kom tau txais cov txheej txheem nyias nyias polymer dielectric (tuab 2 μm), cov kua SEBS toluene (80 mg / ml) tau coated rau ntawm octadecyltrichlorosilane (OTS) - hloov kho SiO2 / Si substrate ntawm 1000 rpm rau 1 feeb. Cov zaj duab xis dielectric nyias tuaj yeem yooj yim hloov pauv los ntawm qhov chaw hydrophobic OTS mus rau SEBS substrate uas npog nrog graphene uas tau npaj tseg. Lub capacitor tuaj yeem ua los ntawm kev tso cov kua-hlau (EGaIn; Sigma-Aldrich) sab saum toj electrode los txiav txim siab qhov capacitance ua haujlwm ntawm kev ntxhov siab siv lub ntsuas LCR (inductance, capacitance, resistance) (Agilent). Lwm qhov ntawm transistor muaj cov polymer-sorted semiconducting CNTs, ua raws li cov txheej txheem tau tshaj tawm yav dhau los (53). Cov electrod qhov chaw/qhov dej ntws uas muaj qauv tau tsim rau ntawm cov khoom siv SiO2/Si uas ruaj khov. Tom qab ntawd, ob ntu, dielectric/G/SEBS thiab CNTs/patterned G/SiO2/Si, tau raug laminated rau ib leeg, thiab ntub rau hauv BOE kom tshem tawm cov khoom siv SiO2/Si uas ruaj khov. Yog li, cov transistors uas pom tseeb thiab ncab tau tau tsim. Kev sim hluav taws xob hauv qab kev ntxhov siab tau ua tiav ntawm kev teeb tsa ncab tes raws li txoj kev tau hais los saum toj no.
Cov ntaub ntawv ntxiv rau tsab xov xwm no muaj nyob rau ntawm http://advances.sciencemag.org/cgi/content/full/3/9/e1700159/DC1
daim duab S1. Cov duab thaij los ntawm lub tshuab tsom iav ntawm cov monolayer MGG ntawm SiO2/Si substrates ntawm ntau qhov loj sib txawv.
daim duab S4. Kev sib piv ntawm ob-probe daim ntawv tiv thaiv thiab transmittances @550 nm ntawm mono-, bi- thiab trilayer plain graphene (dub squares), MGG (liab voj voog), thiab CNTs (xiav triangle).
daim duab S7. Kev hloov pauv tsis kam ntawm mono- thiab bilayer MGGs (dub) thiab G (liab) nyob rau hauv ~ 1000 cyclic strain loading txog li 40 thiab 90% parallel strain, raws li.
daim duab S10. Daim duab SEM ntawm trilayer MGG ntawm SEBS elastomer tom qab kev ncab, qhia txog kev sib tshuam ntev hla ntau qhov tawg.
daim duab S12. Daim duab AFM ntawm peb txheej MGG ntawm SEBS elastomer nyias heev ntawm 20% strain, qhia tias ib daim ntawv hla hla ib qho tawg.
rooj S1. Kev txav mus los ntawm bilayer MGG-ib-walled carbon nanotube transistors ntawm ntau qhov ntev ntawm cov channel ua ntej thiab tom qab kev ntxhov siab.
Qhov no yog ib tsab xov xwm qhib rau kev nkag mus tau raws li cov nqe lus ntawm daim ntawv tso cai Creative Commons Attribution-NonCommercial, uas tso cai siv, faib tawm, thiab rov ua dua tshiab hauv txhua qhov chaw, tsuav yog qhov kev siv tsis yog rau kev lag luam thiab muab cov haujlwm thawj zaug raug hais kom raug.
LUS CEEV: Peb tsuas thov koj qhov chaw nyob email kom tus neeg uas koj pom zoo rau nplooj ntawv ntawd paub tias koj xav kom lawv pom nws, thiab nws tsis yog cov ntawv xa tsis raug cai. Peb tsis khaws cov chaw nyob email twg li.
Lo lus nug no yog rau kev sim seb koj puas yog tib neeg tuaj xyuas thiab tiv thaiv kev xa cov ntawv spam tsis siv neeg.
Los ntawm Nan Liu, Alex Chortos, Ting Lei, Lihua Jin, Taeho Roy Kim, Won-Gyu Bae, Chenxin Zhu, Sihong Wang, Raphael Pfattner, Xiyuan Chen, Robert Sinclair, Zhenan Bao
Los ntawm Nan Liu, Alex Chortos, Ting Lei, Lihua Jin, Taeho Roy Kim, Won-Gyu Bae, Chenxin Zhu, Sihong Wang, Raphael Pfattner, Xiyuan Chen, Robert Sinclair, Zhenan Bao
© 2021 American Association for the Advancement of Science. Txhua txoj cai. AAAS yog ib tug khub ntawm HINARI, AGORA, OARE, CHORUS, CLOCKSS, CrossRef thiab COUNTER.Science Advances ISSN 2375-2548.
Lub sijhawm tshaj tawm: Lub Ib Hlis-28-2021