Ultratransparent thiab stretchable graphene electrodes

Cov khoom siv ob sab, xws li graphene, yog qhov txaus nyiam rau ob qho tib si cov khoom siv semiconductor thiab cov ntawv siv nascent hauv cov khoom siv hluav taws xob hloov tau yooj yim. Txawm li cas los xij, lub zog tensile siab ntawm graphene ua rau tawg ntawm qhov qis qis, ua rau nws nyuaj rau kev ua kom zoo dua ntawm nws cov khoom siv hluav taws xob txawv txawv hauv cov khoom siv hluav taws xob. Txhawm rau kom muaj kev ua tau zoo ntawm kev ua haujlwm zoo ntawm cov pob tshab graphene conductors, peb tsim graphene nanoscrolls nyob nruab nrab ntawm cov txheej graphene stacked, hu ua multilayer graphene / graphene scrolls (MGGs). Nyob rau hauv kev nyuaj siab, qee qhov scrolls txuas cov fragmented domains ntawm graphene kom tswj tau ib tug percolating network uas enabled zoo heev conductivity ntawm high strains. Trilayer MGGs txhawb nqa ntawm elastomers khaws 65% ntawm lawv cov thawj coj ntawm 100% strain, uas yog perpendicular rau cov kev taw qhia ntawm tam sim no ntws, whereas trilayer films ntawm graphene tsis muaj nanoscrolls khaws cia tsuas yog 25% ntawm lawv pib conductance. Lub stretchable all- carbon transistor fabricated siv MGGs raws li electrodes pom ib tug transmittance ntawm> 90% thiab khaws 60% ntawm nws thawj tam sim no tso zis ntawm 120% strain (sib npaug rau cov kev taw qhia ntawm tus nqi thauj). Cov no muaj zog stretchable thiab pob tshab tag nrho-carbon transistors tuaj yeem ua kom cov khoom siv hluav taws xob stretchable optoelectronics.
Stretchable transparent electronics yog ib thaj chaw loj hlob uas muaj cov ntawv thov tseem ceeb hauv cov tshuab biointegrated siab heev (1, 2) nrog rau lub peev xwm los koom ua ke nrog stretchable optoelectronics (3, 4) los tsim cov khoom muag muag muag thiab cov lus qhia. Graphene nthuav tawm cov khoom tsim nyog ntawm atomic thickness, siab transparency, thiab siab conductivity, tab sis nws cov kev siv nyob rau hauv stretchable daim ntaub ntawv tau inhibited los ntawm nws nyiam tawg ntawm me me hom. Kev kov yeej cov kev txwv ntawm cov graphene tuaj yeem ua kom muaj kev ua haujlwm tshiab hauv cov khoom siv pob tshab.
Cov khoom tshwj xeeb ntawm graphene ua rau nws muaj zog sib tw rau tiam tom ntej ntawm pob tshab conductive electrodes (5, 6). Piv nrog rau feem ntau siv pob tshab conductor, indium tin oxide [ITO; 100 ohms/square (sq) ntawm 90% pob tshab], monolayer graphene zus los ntawm tshuaj vapor deposition (CVD) muaj ib tug zoo sib xws ntawm daim ntawv kuj (125 ohms / sq) thiab pob tshab (97.4%) (5). Tsis tas li ntawd, graphene films muaj qhov yooj yim tshaj plaws piv rau ITO (7). Piv txwv li, ntawm cov yas substrate, nws cov conductance tuaj yeem khaws cia txawm tias lub vojvoog khoov ntawm curvature me me li 0.8 hli (8). Txhawm rau txhim kho nws cov hluav taws xob ua tau zoo raws li cov pob tshab hloov pauv hloov pauv, cov haujlwm yav dhau los tau tsim cov khoom siv graphene hybrid nrog ib qho -dimensional (1D) nyiaj nanowires lossis carbon nanotubes (CNTs) (9–11). Ntxiv mus, graphene tau raug siv los ua electrodes rau sib xyaw heterostructural semiconductors (xws li 2D bulk Si, 1D nanowires / nanotubes, thiab 0D quantum dots) (12), hloov pauv hloov pauv, hnub ci hlwb, thiab lub teeb emitting diodes (LEDs) (13). —23).
Txawm hais tias graphene tau pom cov txiaj ntsig zoo rau cov khoom siv hluav taws xob hloov tau yooj yim, nws daim ntawv thov hauv cov khoom siv hluav taws xob stretchable tau txwv los ntawm nws cov khoom siv tshuab (17, 24, 25); graphene muaj qhov nruj hauv dav hlau ntawm 340 N / m thiab Young's modulus ntawm 0.5 TPa (26). Lub zog carbon-carbon network tsis muaj lub zog dissipation mechanisms rau kev siv strain thiab yog li yooj yim tawg ntawm tsawg dua 5% strain. Piv txwv li, CVD graphene pauv mus rau polydimethylsiloxane (PDMS) elastic substrate tsuas tuaj yeem tuav nws cov conductivity tsawg dua 6% strain (8). Theoretical xam pom tias crumpling thiab interplay ntawm cov khaubncaws sab nraud povtseg sib txawv yuav tsum muaj zog txo cov tawv nqaij (26). Los ntawm stacking graphene rau hauv ntau cov khaubncaws sab nraud povtseg, nws tau tshaj tawm tias qhov bi- lossis trilayer graphene yog stretchable mus rau 30% strain, exhibiting kuj hloov 13 npaug me dua li ntawm monolayer graphene (27). Txawm li cas los xij, qhov stretchability no tseem muaj qhov tsis zoo rau lub xeev-of-the-art stretchable c onductors (28, 29).
Transistors yog ib qho tseem ceeb hauv kev siv stretchable vim hais tias lawv pab kom sophisticated sensor readout thiab teeb liab tsom xam (30, 31). Transistors ntawm PDMS nrog multilayer graphene raws li qhov chaw / ntws electrodes thiab cov khoom siv channel tuaj yeem tswj tau hluav taws xob ua haujlwm txog li 5% strain (32), uas yog qhov tseem ceeb hauv qab tus nqi qis kawg nkaus (~ 50%) rau cov khoom siv saib xyuas kev noj qab haus huv thiab cov tawv nqaij hluav taws xob ( 33, 34). Tsis ntev los no, txoj hauv kev graphene kirigami tau tshawb pom, thiab cov transistor gated los ntawm cov kua electrolyte tuaj yeem ncav cuag ntau npaum li 240% (35). Txawm li cas los xij, txoj kev no yuav tsum tau tshem tawm graphene, uas ua rau cov txheej txheem tsim khoom nyuaj.
Ntawm no, peb ua tiav cov khoom siv graphene zoo heev los ntawm kev sib cuam tshuam graphene scrolls (~ 1 txog 20 μm ntev, ~ 0.1 txog 1 μm dav, thiab ~ 10 mus rau 100 nm siab) nyob nruab nrab ntawm cov txheej graphene. Peb xav tias cov graphene scrolls tuaj yeem muab txoj hauv kev rau cov kab nrib pleb hauv cov nplooj ntawv graphene, yog li tswj xyuas cov khoom siv hluav taws xob siab. Cov graphene scrolls tsis xav tau kev sib txuas ntxiv lossis txheej txheem; lawv yog ib txwm tsim thaum lub sij hawm ntub dej hloov txheej txheem. Los ntawm kev siv multilayer G / G (graphene / graphene) scrolls (MGGs) graphene stretchable electrodes (qhov chaw / dej thiab rooj vag) thiab semiconducting CNTs, peb muaj peev xwm ua kom pom tseeb pob tshab thiab siab stretchable all-carbon transistors, uas yuav ncav cuag 120 % strain (piav mus rau cov kev taw qhia ntawm tus nqi thauj khoom) thiab khaws 60% ntawm lawv cov khoom qub tam sim no. Qhov no yog qhov feem ntau stretchable pob tshab carbon-raws li transistor kom deb li deb, thiab nws muab txaus tam sim no tsav lub inorganic LED.
Txhawm rau pab kom thaj chaw loj pob tshab stretchable graphene electrodes, peb xaiv CVD-loj graphene ntawm Cu ntawv ci. Cov ntawv ci Cu tau raug tshem tawm hauv nruab nrab ntawm CVD quartz raj kom tso cai rau kev loj hlob ntawm graphene ntawm ob sab, tsim G / Cu / G cov qauv. Txhawm rau hloov graphene, peb thawj zaug spin-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 lwm sab ntawm graphene), thiab tom qab ntawd, Tag nrho cov yeeb yaj kiab (PMMA / sab saum toj graphene / Cu / hauv qab graphene) tau tsau rau hauv (NH4) 2S2O8 tov kom tshem tawm cov ntawv ci Cu. Sab hauv qab-sab graphene yam tsis muaj PMMA txheej yuav tsis muaj kev sib tsoo thiab qhov tsis xws luag uas tso cai rau kev nkag mus rau hauv (36, 37). Raws li tau piav qhia hauv daim duab 1A, nyob rau hauv qhov cuam tshuam ntawm qhov nro, cov graphene tso tawm tau dov mus rau hauv scrolls thiab tom qab txuas mus rau sab saum toj-G / PMMA zaj duab xis. Sab saum toj-G / G scrolls tuaj yeem raug xa mus rau txhua lub substrate, xws li SiO2 / Si, iav, lossis mos polymer. Rov ua cov txheej txheem hloov pauv no ntau zaus mus rau tib lub substrate muab MGG cov qauv.
(A) Schematic illustration ntawm cov txheej txheem fabrication rau MGGs raws li ib tug stretchable electrode. Thaum lub sij hawm hloov graphene, backside graphene ntawm Cu ntawv ci tau tawg ntawm ciam teb thiab qhov tsis xws luag, dov mus rau hauv cov duab arbitrary, thiab nruj nreem txuas mus rau sab sauv zaj duab xis, tsim nanoscrolls. Plaub daim duab tas luav qhia txog cov qauv MGG stacked. (B thiab C) High-resolution TEM characterizations ntawm ib tug monolayer MGG, tsom rau lub monolayer graphene (B) thiab cov scroll (C) cheeb tsam, raws li. Lub inset ntawm (B) yog ib tug tsawg-magnification duab uas qhia tag nrho morphology ntawm monolayer MGGs nyob rau hauv daim phiaj TEM. Insets ntawm (C) yog cov kev siv zog siv nyob rau hauv cov thawv duab plaub uas tau qhia hauv daim duab, qhov kev ncua deb ntawm lub dav hlau atomic yog 0.34 thiab 0.41 nm. (D) Carbon K-ntug EEL spectrum nrog cov yam ntxwv graphitic π * thiab σ* peaks sau npe. (E) Sectional AFM duab ntawm monolayer G / G scrolls nrog qhov siab profile raws kab daj dotted. (F mus rau I) Optical microscopy thiab AFM duab s ntawm trilayer G tsis muaj (F thiab H) thiab nrog scrolls (G thiab kuv) ntawm 300-nm-tuab SiO2 / Si substrates, feem. Cov neeg sawv cev scrolls thiab wrinkles tau sau los qhia txog lawv qhov sib txawv.
Txhawm rau kom paub tseeb tias cov scrolls yog dov graphene nyob rau hauv qhov xwm txheej, peb tau ua qhov kev daws teeb meem siab kis tau tus mob electron microscopy (TEM) thiab electron zog poob (EEL) spectroscopy kev tshawb fawb ntawm monolayer sab saum toj-G / G scroll qauv. Daim duab 1B qhia txog cov qauv hexagonal ntawm monolayer graphene, thiab lub inset yog tag nrho cov morphology ntawm zaj duab xis npog ntawm ib lub qhov carbon ntawm TEM daim phiaj. Lub monolayer graphene spans feem ntau ntawm daim phiaj, thiab ib co graphene flakes nyob rau hauv lub xub ntiag ntawm ntau pawg ntawm hexagonal rings tshwm (Fig. 1B). Los ntawm kev ua kom zoo rau hauv ib tus neeg scroll (Daim duab 1C), peb tau pom ntau qhov ntawm graphene lattice fringes, nrog rau cov lattice spacing nyob rau hauv thaj tsam ntawm 0.34 txog 0.41 nm. Cov kev ntsuas no qhia tias cov flakes yog random dov thiab tsis zoo tag nrho graphite, uas muaj ib tug lattice spacing ntawm 0.34 nm nyob rau hauv "ABAB" txheej stacking. Daim duab 1D qhia txog cov pa roj carbon K-ntug EEL spectrum, qhov twg lub ncov ntawm 285 eV pib los ntawm π * orbital thiab lwm qhov ib ncig ntawm 290 eV yog vim qhov kev hloov ntawm σ* orbital. Nws tuaj yeem pom tias sp2 bonding dominates nyob rau hauv cov qauv no, xyuas kom meej tias cov scrolls yog heev graphitic.
Optical microscopy thiab atomic force microscopy (AFM) cov duab muab kev nkag siab rau kev faib tawm ntawm graphene nanoscrolls hauv MGGs (Fig. 1, E rau G, thiab figs. S1 thiab S2). Cov scrolls yog randomly faib nyob rau saum npoo, thiab lawv nyob rau hauv-plane ntom ntom tsub kom proportionally rau tus naj npawb ntawm stacked txheej. Ntau cov scrolls yog tangled rau hauv pob caus thiab nthuav tawm qhov siab tsis sib xws hauv thaj tsam ntawm 10 txog 100 nm. Lawv yog 1 mus rau 20 μm ntev thiab 0.1 mus rau 1 μm dav, nyob ntawm seb qhov ntau thiab tsawg ntawm lawv thawj graphene flakes. Raws li pom nyob rau hauv daim duab 1 (H thiab kuv), cov scrolls muaj qhov ntau thiab tsawg dua cov wrinkles, ua rau ib tug ntau rougher interface nyob rau hauv nruab nrab ntawm graphene txheej.
Txhawm rau ntsuas cov khoom siv hluav taws xob, peb ua qauv graphene films nrog lossis tsis muaj cov qauv scroll thiab txheej txheej txheej rau hauv 300-μm-dav thiab 2000-μm-ntev strips siv photolithography. Ob-kev sojntsuam tsis kam raws li kev ua haujlwm ntawm kev lim dej tau ntsuas nyob rau hauv ib puag ncig. Lub xub ntiag ntawm scrolls txo cov resistivity rau monolayer graphene los ntawm 80% nrog tsuas yog ib tug 2.2% txo nyob rau hauv lub transmittance (daim duab S4). Qhov no tau lees paub tias nanoscrolls, uas muaj qhov ceev tam sim no mus txog 5 × 107 A / cm2 (38, 39), ua kom muaj hluav taws xob zoo heev rau MGGs. Ntawm tag nrho cov mono-, bi-, thiab trilayer dawb graphene thiab MGGs, trilayer MGG muaj qhov zoo tshaj plaws conductance nrog lub pob tshab ntawm yuav luag 90%. Txhawm rau sib piv nrog lwm qhov chaw ntawm graphene tau tshaj tawm hauv cov ntaub ntawv, peb kuj tau ntsuas plaub qhov kev sojntsuam daim ntawv tsis kam (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 hais tias piv los yog siab dua conductivity thiab pob tshab tshaj li artificially stacked multila yer dawb graphene thiab txo graphene oxide (RGO) (6, 8, 18). Nco ntsoov tias daim ntawv tsis kam ntawm cov khoom siv sib xyaw ua ke ntau txheej graphene dawb los ntawm cov ntaub ntawv yog me ntsis siab dua li ntawm peb MGG, tej zaum yog vim lawv qhov kev loj hlob tsis zoo thiab hloov txoj kev.
(A) Plaub-kab ntawv tiv thaiv tiv thaiv kev xa tawm ntawm 550 nm rau ntau hom graphene, qhov twg cov squares dub qhia txog mono-, bi-, thiab trilayer MGGs; Lub voj voog liab thiab xiav daim duab peb sab sib haum nrog ntau txheej graphene loj hlob ntawm Cu thiab Ni los ntawm kev tshawb fawb ntawm Li li al. (6) Kim EJ et al. (8), feem, thiab tom qab ntawd xa mus rau SiO2 / Si lossis quartz; thiab cov duab peb sab ntsuab yog qhov tseem ceeb rau RGO ntawm qhov sib txawv txo qib los ntawm kev kawm ntawm Bonaccorso li al. (18). (B thiab C) Kev hloov pauv tsis zoo ntawm mono-, bi- thiab trilayer MGGs thiab G raws li kev ua haujlwm ntawm perpendicular (B) thiab parallel (C) strain rau cov kev taw qhia ntawm tam sim no ntws. (D) Kev hloov pauv tsis zoo ntawm bilayer G (liab) thiab MGG (dub) nyob rau hauv cov kab mob cyclic loading txog 50% perpendicular strain. (E) Kev hloov pauv tsis zoo ntawm trilayer G (liab) thiab MGG (dub) nyob rau hauv cov kab mob cyclic loading mus txog 90% cov kab mob sib npaug. (F) Normalized capacitance hloov pauv ntawm mono-, bi- thiab trilayer G thiab bi- thiab trilayer MGGs raws li kev ua haujlwm n ntawm strain. Lub inset yog cov qauv capacitor, qhov twg cov polymer substrate yog SEBS thiab polymer dielectric txheej yog 2-μm-thick SEBS.
Txhawm rau ntsuas qhov kev ua tau zoo ntawm MGG, peb hloov graphene mus rau thermoplastic elastomer styrene-ethylene-butadiene-styrene (SEBS) substrates (~ 2 cm dav thiab ~ 5 cm ntev), thiab cov conductivity raug ntsuas raws li lub substrate tau stretched. (saib Cov Khoom Siv thiab Cov Txheej Txheem) ob qho tib si perpendicular thiab parallel rau cov kev taw qhia ntawm cov dej ntws tam sim no (Fig. 2, B thiab C). Kev coj cwj pwm ntawm cov hluav taws xob strain tau txhim kho nrog kev koom ua ke ntawm nanoscrolls thiab nce tus lej ntawm graphene txheej. Piv txwv li, thaum strain yog perpendicular mus rau tam sim no ntws, rau monolayer graphene, qhov sib ntxiv ntawm scrolls nce lub strain ntawm hluav taws xob breakage ntawm 5 mus rau 70%. Lub strain kam rau ua ntawm trilayer graphene kuj tseem txhim kho zoo dua piv nrog cov monolayer graphene. Nrog nanoscrolls, ntawm 100% perpendicular strain, qhov tsis kam ntawm trilayer MGG qauv tsuas yog nce los ntawm 50%, piv rau 300% rau trilayer graphene yam tsis muaj scrolls. Kev hloov pauv nyob rau hauv cyclic strain load ing tau tshawb xyuas. Rau kev sib piv (Daim duab 2D), qhov kev tawm tsam ntawm cov yeeb yaj kiab bilayer graphene tau nce li ntawm 7.5 zaug tom qab ~ 700 cycles ntawm 50% perpendicular strain thiab nce ntxiv nrog rau cov kab mob hauv txhua lub voj voog. Ntawm qhov tod tes, qhov kev tawm tsam ntawm bilayer MGG tsuas yog nce txog 2.5 npaug tom qab ~ 700 cycles. Ua ntawv thov txog li 90% strain raws cov kev taw qhia thaum uas tig mus, qhov kev tiv thaiv ntawm trilayer graphene nce ~ 100 zaug tom qab 1000 cycles, whereas nws tsuas yog ~ 8 zaug hauv trilayer MGG (Fig. 2E). Cycling tau tshwm sim nyob rau hauv daim duab. S7. Qhov nce nrawm dua nyob rau 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 cov kev taw qhia ntawm cov dej ntws tam sim no. Qhov sib txawv ntawm kev ua hauj lwm thaum lub sij hawm thauj khoom thiab unloading strain yog vim viscoelastic rov qab ntawm SEBS elastomer substrate. Lub zog ruaj khov ntawm MGG strips thaum caij tsheb kauj vab yog vim muaj cov ntawv loj loj uas tuaj yeem txuas rau qhov tawg ntawm cov graphene (raws li obse rved los ntawm AFM), pab tswj txoj hauv kev percolating. Qhov no tshwm sim ntawm kev tuav tswj conductivity los ntawm ib tug percolating txoj kev tau qhia ua ntej rau tawg hlau los yog semiconductor films ntawm elastomer substrates (40, 41).
Txhawm rau soj ntsuam cov graphene-raws li cov yeeb yaj kiab raws li lub rooj vag electrodes hauv cov khoom siv stretchable, peb npog cov graphene txheej nrog SEBS dielectric txheej (2 μm tuab) thiab saib xyuas cov dielectric capacitance hloov raws li kev ua haujlwm ntawm strain (saib daim duab 2F thiab cov khoom siv ntxiv rau. paub meej). Peb pom tias capacitances nrog dawb monolayer thiab bilayer graphene electrodes poob sai sai vim yog poob ntawm hauv dav hlau conductivity ntawm graphene. Nyob rau hauv sib piv, capacitances gated los ntawm MGGs raws li zoo raws li dawb trilayer graphene pom ib tug nce ntawm capacitance nrog strain, uas yuav tsum tau vim yog txo nyob rau hauv dielectric thickness nrog strain. Qhov kev cia siab nce hauv capacitance zoo sib xws nrog cov qauv MGG (daim duab S8). Qhov no qhia tau hais tias MGG yog haum raws li lub rooj vag electrode rau stretchable transistors.
Txhawm rau tshawb xyuas ntxiv txog lub luag haujlwm ntawm 1D graphene scroll ntawm qhov kev ua siab ntev ntawm cov hluav taws xob conductivity thiab tswj kev sib cais ntawm cov txheej graphene, peb siv cov tshuaj tsuag-coated CNTs los hloov cov graphene scrolls (saib Cov Khoom Siv Ntxiv ). Txhawm rau ua raws li MGG cov qauv, peb tso peb qhov ceev ntawm CNTs (uas yog, CNT1.
(A txog C) AFM cov duab ntawm peb qhov sib txawv ntawm CNTs (CNT1
Txhawm rau kom nkag siab ntxiv txog lawv lub peev xwm ua cov khoom siv hluav taws xob rau cov khoom siv hluav taws xob, peb tau tshawb xyuas cov morphologies ntawm MGG thiab G-CNT-G nyob rau hauv strain. Optical microscopy thiab scanning electron microscopy (SEM) tsis yog txoj hauv kev ua haujlwm zoo vim tias ob qho tib si tsis muaj xim sib txawv thiab SEM raug rau cov duab kos duab thaum lub sij hawm electron scanning thaum graphene nyob rau hauv polymer substrates (fig. S9 thiab S10). Txhawm rau soj ntsuam nyob rau hauv qhov chaw graphene nto nyob rau hauv txoj kev, peb tau sau AFM ntsuas ntawm trilayer MGGs thiab graphene dawb tom qab hloov mus rau nyias nyias (~ 0.1 hli tuab) thiab elastic SEBS substrates. Vim yog qhov tsis xws luag hauv CVD graphene thiab extrinsic kev puas tsuaj thaum lub sij hawm hloov cov txheej txheem, cov kab nrib pleb yog inevitably generated ntawm cov strained graphene, thiab nrog nce strain, cov kab nrib pleb ua denser (Fig. 4, A rau D). Nyob ntawm cov txheej txheem stacking ntawm cov pa roj carbon-based electrodes, cov kab nrib pleb nthuav tawm txawv morphologies (daim duab S11) (27). Thaj chaw thaj chaw ntom ntom (txhais tau tias thaj chaw tawg / tshuaj ntsuam xyuas) ntawm cov monolayer graphene tom qab sib xws rau cov hluav taws xob conduction rau mggs. Ntawm qhov tod tes, scrolls feem ntau pom los txuas cov kab nrib pleb, muab txoj hauv kev ntxiv rau hauv cov yeeb yaj kiab strained. Piv txwv li, raws li daim ntawv lo rau hauv daim duab ntawm daim duab 4B, ib tug dav scroll hla ib tug tawg nyob rau hauv lub trilayer MGG, tab sis tsis muaj scroll tau pom nyob rau hauv lub tiaj graphene (Fig. 4, E mus rau H). Ib yam li ntawd, CNTs kuj txuas cov kab nrib pleb hauv graphene (daim duab S11). Qhov chaw tawg ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom, thiab kev sib tw ntawm cov yeeb yaj kiab yog qhia hauv Daim Duab 4K.
(A txog H) Nyob rau hauv qhov chaw AFM cov duab ntawm trilayer G / G scrolls (A txog D) thiab trilayer G cov qauv (E txog H) ntawm SEBS nyias nyias (~ 0.1 hli tuab) elastomer ntawm 0, 20, 60, thiab 100 % zog. Cov neeg sawv cev cov kab nrib pleb thiab scrolls yog taw tes nrog cov xub. Tag nrho cov duab AFM yog nyob rau hauv ib cheeb tsam ntawm 15 μm × 15 μm, siv tib xim scale bar raws li daim ntawv lo. (I) Simulation geometry ntawm cov qauv monolayer graphene electrodes ntawm SEBS substrate . (J) Simulation contour daim ntawv qhia ntawm lub siab tshaj plaws tus thawj coj logarithmic strain nyob rau hauv lub monolayer graphene thiab SEBS substrate ntawm 20% lwm hom. (K) Kev sib piv ntawm cov chaw tawg ntom ntom ntom ntom ntom (cov kab liab), kos sab nrauv), thiab kem nteg ntom (xiav sab) rau cov duab graphene sib txawv.
Thaum MGG cov yeeb yaj kiab tau ncab, muaj ib qho tseem ceeb ntxiv mechanism uas cov scrolls tuaj yeem txuas rau thaj tsam tawg ntawm graphene, tuav lub network percolating. Cov graphene scrolls tau cog lus vim tias lawv tuaj yeem ua tau kaum ntawm micrometers ntev thiab yog li tuaj yeem txuas cov kab nrib pleb uas feem ntau mus txog micrometer. Tsis tas li ntawd, vim hais tias cov scrolls muaj ntau txheej ntawm graphene, lawv yuav tsum muaj qhov tsis zoo. Hauv kev sib piv, kuj tseem ntom ntom (qis xa tawm) CNT tes hauj lwm yuav tsum tau muab cov kev sib piv sib piv, vim tias CNTs me dua (feem ntau yog ob peb micrometers ntev) thiab tsis tshua muaj hluav taws xob ntau dua li scrolls. Ntawm qhov tod tes, raws li qhia hauv daim duab. S12, whereas lub graphene tawg thaum lub sij hawm ncab kom haum raws li cov kev sib tw, cov scrolls tsis tawg, qhia tias tom kawg yuav zawv zawg rau hauv qab graphene. Qhov laj thawj uas lawv tsis tawg yog qhov yuav yog vim cov qauv dov, muaj ntau txheej ntawm graphene (~ 1 txog 2 0 μm ntev, ~ 0.1 txog 1 μm dav, thiab ~ 10 mus rau 100 nm siab), uas muaj ib tug zoo dua modulus tshaj ib txheej graphene. Raws li tau tshaj tawm los ntawm Green thiab Hersam (42), hlau CNT tes hauj lwm (tube txoj kab uas hla ntawm 1.0 nm) tuaj yeem ua tiav cov ntawv tsis tshua muaj zog <100 ohms / sq. Xav tias peb cov graphene scrolls muaj qhov dav ntawm 0.1 mus rau 1 μm thiab tias G / G scrolls muaj ntau qhov chaw sib cuag loj dua li CNTs, qhov kev tiv thaiv thiab kev sib cuag ntawm graphene thiab graphene scrolls yuav tsum tsis txhob txwv cov yam ntxwv kom muaj kev sib cuag siab.
Lub graphene muaj ntau dua modulus tshaj SEBS substrate. Txawm hais tias qhov ua tau zoo ntawm cov graphene electrode yog qis dua li ntawm cov substrate, qhov nruj ntawm lub graphene lub sij hawm nws cov tuab yog piv rau cov substrate (43, 44), uas ua rau muaj kev cuam tshuam nruab nrab ntawm cov kob. Peb simulated qhov deformation ntawm 1-nm-thick graphene ntawm SEBS substrate (saib Cov Khoom Siv Ntxiv rau cov ntsiab lus). Raws li cov txiaj ntsig simulation, thaum 20% strain raug siv rau SEBS substrate sab nraud, qhov nruab nrab ntawm cov graphene yog ~ 6.6% (Daim duab 4J thiab daim duab S13D), uas yog raws li kev soj ntsuam kev soj ntsuam (saib daim duab S13) . Peb piv cov hom kab mob hauv cov qauv graphene thiab substrate cheeb tsam siv optical microscopy thiab pom cov kab mob nyob rau hauv lub substrate cheeb tsam yuav tsum muaj tsawg kawg yog ob zaug ntawm cov kab mob nyob rau hauv lub graphene cheeb tsam. Qhov no qhia tau hais tias cov strain siv rau ntawm graphene electrode qauv tuaj yeem raug kaw, tsim graphene tawv Islands tuaj rau saum SEBS (26, 43, 44).
Yog li ntawd, lub peev xwm ntawm MGG electrodes kom tswj tau siab conductivity nyob rau hauv siab strain yog yuav enabled los ntawm ob tug loj mechanisms: (i) cov scrolls yuav choj disconnected cheeb tsam kom muaj ib tug conductive percolation txoj kev, thiab (ii) cov multilayer graphene nplooj / elastomer yuav swb. dhau ib leeg, ua rau txo qis ntawm graphene electrodes. Rau ntau cov khaubncaws sab nraud povtseg ntawm hloov graphene ntawm elastomer, cov khaubncaws sab nraud povtseg tsis muaj zog txuas nrog ib leeg, uas tuaj yeem xaub hauv cov lus teb rau strain (27). Cov scrolls kuj nce qhov roughness ntawm graphene txheej, uas yuav pab kom muaj kev sib cais ntawm graphene txheej thiab yog li pab kom zawv zawg ntawm graphene txheej.
Tag nrho cov khoom siv roj carbon monoxide tau zoo siab nrhiav vim tias tus nqi qis thiab cov khoom siv siab. Nyob rau hauv peb cov ntaub ntawv, tag nrho cov-carbon transistors tau fabricated siv lub hauv qab graphene rooj vag, ib tug sab saum toj graphene qhov chaw/drain contact, ib tug sorted CNT semiconductor, thiab SEBS raws li ib tug dielectric (Fig. 5A). Raws li pom nyob rau hauv daim duab 5B, ib tug tag nrho-carbon ntaus ntawv nrog CNTs raws li qhov chaw/drain thiab rooj vag (hauv qab ntaus ntawv) yog opaque ntau tshaj li cov cuab yeej nrog graphene electrodes (sab saum toj ntaus ntawv). Qhov no yog vim hais tias CNT tes hauj lwm yuav tsum tau loj thicknesses thiab, yog li ntawd, qis optical transmittances kom tiav daim ntawv resistances zoo li cov graphene (daim duab S4). Daim duab 5 (C thiab D) qhia cov neeg sawv cev hloov chaw thiab cov zis nkhaus ua ntej strain rau lub transistor ua nrog bilayer MGG electrodes. Qhov dav thiab qhov ntev ntawm cov 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 10-5 thiab 10-8 A, feem. Cov zis nkhaus nthuav tawm qhov zoo tshaj plaws linear thiab sa turation regimes nrog lub rooj vag-voltage dependence, qhia qhov zoo tshaj plaws kev sib cuag ntawm CNTs thiab graphene electrodes (45). Kev tiv thaiv kev tiv thaiv nrog graphene electrodes tau pom tias qis dua li cov evaporated Au zaj duab xis (saib daim duab S14). Lub saturation txav ntawm lub stretchable transistor yog hais txog 5.6 cm2 / Vs, zoo ib yam li cov tib polymer-sorted CNT transistors ntawm nruj Si substrates nrog 300-nm SiO2 raws li ib tug dielectric txheej. Kev txhim kho ntxiv hauv kev mus ncig yog ua tau nrog kev tsim nyog raj ntom ntom thiab lwm hom hlab (46).
(A) Scheme ntawm graphene-raws li stretchable transistor. SWNTs, ib leeg-walled carbon nanotubes. (B) Diam duab ntawm stretchable transistors ua los ntawm graphene electrodes (sab saum toj) thiab CNT electrodes (hauv qab). Qhov txawv ntawm pob tshab yog pom meej meej. (C thiab D) Hloov thiab tso zis nkhaus ntawm graphene-raws li transistor ntawm SEBS ua ntej strain. (E thiab F) Hloov cov nkhaus, ntawm thiab tawm tam sim no, rau / tawm piv, thiab kev txav mus los ntawm graphene-based transistor ntawm ntau hom.
Thaum lub pob tshab, tag nrho cov khoom siv carbon tau ncab nyob rau hauv cov kev taw qhia thaum uas tig mus rau tus nqi thauj mus los, tsawg degradation tau pom txog li 120% strain. Thaum lub sij hawm ncab, kev txav mus los tsis tu ncua ntawm 5.6 cm2 / Vs ntawm 0% strain mus rau 2.5 cm2 / Vs ntawm 120% strain (Fig. 5F). Peb kuj muab piv cov transistor kev ua tau zoo rau qhov sib txawv channel ntev (saib cov lus S1). Qhov tseem ceeb, ntawm qhov loj npaum li 105%, tag nrho cov transistors tseem pom qhov sib piv siab rau / tawm (> 103) thiab kev txav mus los (> 3 cm2 / Vs). Tsis tas li ntawd, peb tau sau tag nrho cov hauj lwm tsis ntev los no ntawm tag nrho cov pa roj carbon transistors (saib cov lus S2) (47–52). Los ntawm kev ua kom zoo tshaj plaws kev tsim khoom ntawm elastomers thiab siv MGGs raws li kev sib cuag, peb cov pa roj carbon transistors tag nrho qhia kev ua tau zoo nyob rau hauv cov nqe lus ntawm kev txav mus los thiab hysteresis nrog rau kev ncab heev.
Raws li daim ntawv thov ntawm lub siab pob tshab thiab stretchable transistor, peb siv nws los tswj ib qho kev hloov ntawm LED (Fig. 6A). Raws li pom hauv daim duab 6B, lub teeb ntsuab LED tuaj yeem pom tau meej meej los ntawm cov khoom siv hluav taws xob stretchable tag nrho cov khoom tso ncaj qha saum toj no. Thaum ncab mus rau ~ 100% (Daim duab 6, C thiab D), lub teeb ci LED tsis hloov, uas yog raws li qhov kev ua tau zoo ntawm transistor tau piav qhia saum toj no (saib zaj duab xis S1). Qhov no yog thawj tsab ntawv ceeb toom ntawm stretchable tswj units ua siv graphene electrodes, qhia ib tug tshiab muaj peev xwm rau graphene stretchable electronics.
(A) Circuit Court ntawm transistor tsav LED. GND, av. (B) Daim duab ntawm lub stretchable thiab pob tshab tag nrho-carbon transistor ntawm 0% lim mounted saum lub ntsuab LED. (C) Tag nrho cov pa roj carbon pob tshab thiab stretchable transistor siv los hloov lub LED yog mounted saum lub LED ntawm 0% (sab laug) thiab ~ 100% lim (txoj cai). Cov xib xub dawb taw tes raws li cov cim daj ntawm lub cuab yeej los qhia qhov kev ncua deb tau ncab. (D) Sab saib ntawm lub stretched transistor, nrog lub LED thawb rau hauv lub elastomer.
Nyob rau hauv xaus, peb tau tsim ib tug pob tshab conductive graphene qauv uas tswj siab conductivity nyob rau hauv loj hom raws li stretchable electrodes, enabled los ntawm graphene nanoscrolls nyob rau hauv nruab nrab ntawm stacked graphene txheej. Cov txheej txheem bi- thiab trilayer MGG electrode ntawm ib qho elastomer tuaj yeem tswj tau 21 thiab 65%, feem, ntawm lawv 0% strain conductivities ntawm ib hom kab mob siab txog 100%, piv rau kev ua tiav ntawm kev ua tiav ntawm 5% strain rau cov monolayer graphene electrodes. . Qhov ntxiv conductive paths ntawm graphene scrolls nrog rau qhov tsis muaj zog ntawm kev sib cuam tshuam ntawm cov khaubncaws sab nraud povtseg ua rau lub superior conductivity stability nyob rau hauv strain. Peb txuas ntxiv siv cov qauv graphene no los tsim tag nrho cov pa roj carbon stretchable transistors. Txog tam sim no, qhov no yog qhov feem ntau stretchable graphene-raws li transistor nrog qhov zoo tshaj plaws pob tshab yam tsis siv buckling. Txawm hais tias txoj kev tshawb fawb tam sim no tau ua los pab kom graphene rau cov khoom siv hluav taws xob stretchable, peb ntseeg tias txoj hauv kev no tuaj yeem txuas mus rau lwm cov ntaub ntawv 2D kom pab txhawb nqa 2D hluav taws xob.
Cov cheeb tsam loj CVD graphene tau cog rau ntawm qhov ncua Cu foils (99.999%; Alfa Aesar) nyob rau hauv lub siab tas li ntawm 0.5 mtorr nrog 50–SCCM (tus qauv cubic centimeter ib feeb) CH4 thiab 20–SCCM H2 ua ntej ntawm 1000 ° C. Ob sab ntawm Cu ntawv ci tau them los ntawm monolayer graphene. Ib txheej nyias ntawm PMMA (2000 rpm; A4, Microchem) tau tig-coated ntawm ib sab ntawm Cu ntawv ci, tsim PMMA / G / Cu ntawv ci / G qauv. Tom qab ntawd, tag nrho cov yeeb yaj kiab tau tsau rau hauv 0.1 M ammonium persulfate [(NH4)2S2O8] daws rau li 2 teev kom tshem tawm cov ntawv Cu. Thaum lub sij hawm tus txheej txheem no, cov tsis muaj kev tiv thaiv backside graphene thawj torre nyob rau hauv lub grain ciam teb thiab ces dov mus rau hauv scrolls vim yog nto nro. Cov scrolls tau txuas mus rau PMMA-txhawb siab graphene zaj duab xis, tsim PMMA / G / G scrolls. Cov yeeb yaj kiab tau tom qab ntxuav hauv dej deionized ob peb zaug thiab muab tso rau ntawm lub hom phiaj substrate, xws li SiO2 / Si lossis yas substrate. Sai li cov yeeb yaj kiab uas txuas nrog rau ntawm lub substrate, cov qauv w raws li txuas ntxiv rau hauv acetone, 1: 1 acetone / IPA (isopropyl cawv), thiab IPA rau 30 s txhua tus kom tshem tawm PMMA. Cov yeeb yaj kiab tau ua kom sov ntawm 100 ° C rau 15 feeb lossis khaws cia rau hauv lub tshuab nqus tsev thaum hmo ntuj kom tshem tawm cov dej ntws tawm ua ntej lwm txheej ntawm G / G scroll raug xa mus rau nws. Cov kauj ruam no yog kom tsis txhob muaj qhov detachment ntawm graphene zaj duab xis los ntawm substrate thiab xyuas kom meej tag nrho cov kev pab them nqi ntawm MGGs thaum lub sij hawm tso tawm ntawm PMMA txheej txheem.
Lub morphology ntawm MGG qauv tau soj ntsuam siv lub tshuab ntsuas qhov muag (Leica) thiab lub tshuab ntsuas hluav taws xob (1 kV; FEI). Lub atomic force microscope (Nanoscope III, Digital Instrument) tau ua haujlwm hauv tapping hom los soj ntsuam cov ntsiab lus ntawm G scrolls. Zaj duab xis pob tshab tau sim los ntawm ultraviolet-pom spectrometer (Agilent Cary 6000i). Rau cov kev ntsuam xyuas thaum lub strain nyob rau hauv perpendicular kev taw qhia ntawm tam sim no ntws, photolithography thiab O2 plasma tau siv los ua qauv graphene qauv rau hauv ib daim hlab (~ 300 μm dav thiab ~ 2000 μm ntev), thiab Au (50 nm) electrodes tau thermally deposited siv. duab ntxoov ntxoo qhov ncauj qhov ntswg ntawm ob qhov kawg ntawm sab ntev. Tom qab ntawd cov graphene strips tau muab tso rau hauv kev sib cuag nrog SEBS elastomer (~ 2 cm dav thiab ~ 5 cm ntev), nrog rau cov axis ntev ntawm cov strips sib npaug 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 tiv tauj. Rau cov kev ntsuas sib npaug sib npaug, cov qauv tsis muaj graphene es (~ 5 × 10 mm) raug xa mus rau SEBS substrates, nrog cov axes ntev sib npaug mus rau sab ntev ntawm SEBS substrate. Rau ob qho tib si, tag nrho G (tsis muaj G scrolls) / SEBS tau ncab ntawm sab ntev ntawm lub elastomer nyob rau hauv phau ntawv apparatus, thiab nyob rau hauv situ, peb ntsuas lawv cov kev hloov pauv nyob rau hauv strain ntawm ib tug soj ntsuam chaw nres tsheb nrog ib tug semiconductor analyzer (Keithley 4200. - SCS).
Lub siab stretchable thiab pob tshab tag nrho-carbon transistors ntawm elastic substrate tau tsim los ntawm cov txheej txheem hauv qab no kom tsis txhob muaj cov organic hnyav puas ntawm polymer dielectric thiab substrate. MGG cov qauv raug xa mus rau SEBS raws li lub rooj vag electrodes. Txhawm rau kom tau txais cov txheej txheem nyias-zaj duab xis polymer dielectric txheej (2 μm tuab), SEBS toluene (80 mg / ml) cov tshuaj tau tig-coated ntawm octadecyltrichlorosilane (OTS)-hloov SiO2 / Si substrate ntawm 1000 rpm rau 1 min. Cov yeeb yaj kiab nyias nyias tuaj yeem hloov tau yooj yim los ntawm hydrophobic OTS nto mus rau SEBS substrate them nrog graphene li npaj. Lub capacitor tuaj yeem tsim los ntawm kev tso cov kua-hlau (EGaIn; Sigma-Aldrich) sab saum toj electrode los txiav txim siab lub peev xwm raws li kev ua haujlwm ntawm strain siv LCR (inductance, capacitance, resistance) meter (Agilent). Lwm qhov ntawm cov transistor muaj xws li polymer-sorted semiconducting CNTs, ua raws li cov txheej txheem qhia yav dhau los (53). Cov qauv ntawm qhov chaw/drain electrod es tau fabricated ntawm nruj SiO2/Si substrates. Tom qab ntawd, ob qhov chaw, dielectric / G / SEBS thiab CNTs / patterned G / SiO2 / Si, tau laminated rau ib leeg, thiab tsau rau hauv BOE kom tshem tawm cov tawv SiO2 / Si substrate. Yog li, cov pob tshab thiab stretchable transistors tau tsim. Kev ntsuam xyuas hluav taws xob nyob rau hauv kev lim dej tau ua los ntawm phau ntawv ncab kev teeb tsa raws li cov lus hais saum toj no.
Cov ntaub ntawv ntxiv rau tsab xov xwm no muaj nyob ntawm http://advances.sciencemag.org/cgi/content/full/3/9/e1700159/DC1
fig. S1. Optical microscopy dluab ntawm monolayer MGG ntawm SiO2 / Si substrates ntawm qhov sib txawv magnifications.
fig. S4. Kev sib piv ntawm ob-kev sojntsuam daim ntawv tiv thaiv thiab xa tawm @ 550 nm ntawm mono-, bi- thiab trilayer tiaj graphene (dub squares), MGG (liab voj voog), thiab CNTs (xiav daim duab peb sab).
fig. S7. Kev hloov pauv tsis zoo ntawm mono- thiab bilayer MGGs (dub) thiab G (liab) hauv qab ~ 1000 cyclic strain loading mus txog 40 thiab 90% parallel strain, feem.
fig. S10. SEM duab ntawm trilayer MGG ntawm SEBS elastomer tom qab strain, uas qhia ib tug ntev scroll hla ntau kab nrib pleb.
fig. S12. AFM duab ntawm trilayer MGG ntawm nyias SEBS elastomer ntawm 20% strain, qhia tias ib tug scroll hla ib tug tawg.
tab S1. Mobilities ntawm bilayer MGG-ib-walled carbon nanotube transistors ntawm txawv channel ntev ua ntej thiab tom qab strain.
Qhov no yog ib tsab xov xwm qhib tau muab faib raws li cov ntsiab lus ntawm Creative Commons Attribution-NonCommercial daim ntawv tso cai, uas tso cai rau siv, faib, thiab luam tawm nyob rau hauv ib qho nruab nrab, tsuav yog qhov tshwm sim ntawm kev siv tsis yog rau kev lag luam kom zoo dua thiab muab cov haujlwm qub kom zoo. hais.
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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
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