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1 Vol Decemer 26 doi:1.138/nture5427 Ptterning orgnic single-crystl trnsistor rrys Alejndro L. Briseno 1,2, Stefn C. B. Mnnsfeld 1, Mng M. Ling 1, Shuhong Liu 1, Ricky J. Tseng 2, Colin Reese 1, Mrk E. Roerts 1, Yng Yng 2, Fred Wudl 2 & Zhenn Bo 1 Field-effect trnsistors mde of orgnic single crystls re idel for studying the chrge trnsport chrcteristics of orgnic semiconductor mterils 1. Their outstnding device performnce 2 8, reltive to tht of trnsistors mde of orgnic thin films, mkes them lso ttrctive cndidtes for electronic pplictions such s ctive mtrix displys nd sensor rrys. These pplictions require miniml cross-tlk etween neighouring devices. In the cse of thin film systems, simple ptterning of the ctive semiconductor lyer 9,1 minimizes cross-tlk. But when using orgnic single crystls, the only pproch currently ville for creting rrys of seprte devices is mnul selection nd plcing of individul crystls process prohiitive for producing devices t high density nd with resonle throughput. In contrst, inorgnic crystls hve een grown in extended rrys 11 13, nd efficient nd lrge-re friction of silicon crystlline islnds with high moilities for electronic pplictions hs een reported 14,15. Here we descrie method for effectively fricting lrge rrys of single crystls of wide rnge of orgnic semiconductor mterils directly onto trnsistor source drin electrodes. We find tht film domins of octdecyltriethoxysilne microcontct-printed onto either clen Si/ surfces or flexile plstic provide control over the nucletion of vpour-grown orgnic single crystls. This llows us to fricte lrge rrys of high-performnce orgnic single-crystl field-effect trnsistors with moilities s high s 2.4 cm 2 V 21 s 21 nd on/off rtios greter thn 1 7, nd devices on flexile sustrtes tht retin their performnce fter significnt ending. These results suggest tht our friction pproch constitutes promising step tht might ultimtely llow us to utilize high-performnce orgnic single-crystl field-effect trnsistors for lrge-re electronics pplictions. Figure 1 illustrtes the single-crystl ptterning process (see Methods for detiled description). First, thick octdecyltriethoxysilne (OTS) films (verge thickness, nm, mesured y ellipsometry) re printed y microcontct printing onto clen /Si sustrte, using polydimethylsiloxne (PDMS) stmp with relief structure in the desired pttern. We note tht lthough the results discussed here minly relte to structures grown on rrys of micrometre-sized OTS squres, it is strightforwrd to crete more-complex OTS film ptterns for single-crystl nucletion (Supplementry Figs 3 nd 6). After film deposition, crystls re grown using vpour trnsport method 16 pplicle to rod rnge of mterils, including high-moility p-type mterils such s rurene, pentcene nd tetrcene, nd n-type mterils such s C 6, fluorinted copper phthlocynine (F 16 CuPc) nd tetrcynoquinodimethne (TCNQ) (Supplementry Fig. 14). We find tht sulimtion of the orgnic mteril nd crystl growth re ccomplished in s little s five minutes for pentcene nd s much s two hours for C 6, nd tht crystl nucletion is restricted to OTS-stmped regions nd not oserved on the ckground. The crystls show strong irefringence in opticl microgrphs recorded under cross-polrized light (Supplementry Fig. 6), confirming their crystlline nture. We lso oserve intense nd nrrow diffrction peks in the X-ry diffrction ptterns of pentcene, rurene nd C 6 single crystls, which re indictive of high degree of crystllinity (Supplementry Figs 5, 8 nd 12). Exmples of rrys of single crystls of pentcene, rurene nd C 6 grown on stmped OTS domins re shown in Fig. 1 d. The growth of discrete single crystls is chieved y controlling the feture size of the printed OTS regions so tht it supports on verge only one crystl nucletion event. In the cse of pentcene, crystl nucletion ctivity s function of the size of the stmped OTS domins ws nlysed y using rrys of OTS squres with res of 25 mm 2 (tht is, mm), 625 mm 2 ( mm), 2,5 mm 2 (5 3 5 mm) nd 1, mm 2 (1 3 1 mm). To ensure tht crystlliztion cn e ccurtely compred on different ctive res, specil PDMS stmp ws fricted contining four different feture sizes on one stmp, thus preventing smple-to-smple vritions. The results re summrized in Fig. 2, which plots the verge numer of nuclei (s counted in numerous fields of ech stmp size) versus the stmped domin re. Within experimentl error, the dt fit line corresponding to constnt nucletion density of out one nucleus per 49 mm 2, or single pentcene crystl per mm domin re. This finding is in good greement with our finding tht the mm stmp (used to generte the rry shown in Fig. 1) yields pproximtely one single crystl per domin. The imges in Fig. 2 show the results of using lrge-re rry of mm stmped OTS domins for controlling pentcene growth, demonstrting tht most ptterns result in the formtion of discrete pentcene single crystls. OTS surfce tretments hve previously een used to pttern pentcene thin films on structured sustrtes. In the cse of preferentil pentcene thin film growth on OTS-treted gold surfce structures 17, selective film growth ws ttriuted to different surfce interctions nd surfce diffusivities. Ptterning sustrtes with OTS nd FDTS ((heptdecfluorotetrhydrodecyl)trichlorosilne) lso results in ptterned growth of pentcene films 9 : within certin window of growth conditions, pentcene forms two-dimensionl islnds (islnds with monolyer-stepped terrces) on the ptterned OTS regions, ut only three-dimensionl islnds (disconnected single grins) in the FDTS-treted regions. These loclly different modes of pentcene film growth were ttriuted to different molecule sustrte interctions. However, the present study investigtes the ptterning of discrete single crystls, rther thn the formtion nd ptterning of thin films 18,19, nd the selectivity chieved in our systems is more likely to e due to the high roughness of the thick OTS-stmped film rther thn to different molecule sustrte interctions rising from contrst in surfce chemistry. This view is supported y tomic force microscope imges typiclly showing n r.m.s. roughness of,15 Å in the stmped OTS domins (Supplementry Fig. 1), nd n r.m.s. roughness of,5å in regions of re. In control experiments 1 Deprtment of Chemicl Engineering, Stnford University, Stnford, Cliforni 9435, USA. 2 Deprtment of Chemistry nd Biochemistry nd Exotic Mterils Institute, Deprtment of Mterils Science nd Engineering, University of Cliforni-Los Angeles, Los Angeles, Cliforni 995, USA. 26 Nture Pulishing Group 913

2 NATURE Vol Decemer 26 using thick OTS films stmped onto vpour-deposited smooth OTS monolyer ckground (r.m.s. roughness,2 Å), pentcene crystls nucleted only in the ptterned regions nd with the sme selectivity s seen with thick OTS film ptterns stmped on re (Supplementry Fig. 15). These oservtions gree with clssicl nucletion theory, which predicts tht the higher surfce energy ssocited with irregulrities such s indentions, step edges or protrusions significntly lowers the rrier to heterogeneous nucletion, reltive to tht on flt surfce 2,21 ; they lso gree with modern phse field theory, which similrly predicts heterogeneous nucletion to fvourly occur on rough surfces 22,23. However, we note tht esides the rough topology of the OTS-stmped domins, the use of rther high sustrte temperture is lso importnt in chieving selective crystl growth. The sustrte temperture, which is only,2 uc lower thn tht of the evportion source, results in higher therml redesorption rte in the re regions thn in the djcent rough OTS regions. Given the lrge numer of molecules required to form stle nucleus t high sustrte tempertures 9,24, nucletion on the re surfce is effectively suppressed. Consequently, the nucletion of crystls is effectively suppressed in smooth regions, while the stmped rough OTS domins ct s effective primry nucletion centres. This interprettion is supported y inspection of the underside of the crystl mking direct contct with the OTS film, which reveled tht the initil nucleus my hve grown from the vlley of the rough OTS film in conforml fshion, with lrge prts of the ottom surfce eing plnr nd in close contct to the sustrte (Supplementry Figs 17, 18). The control over crystl nucletion nd growth provided y the OTS ptterns mkes it possile to grow lrge rrys of crystls directly onto trnsistor source drin electrodes (see lso Methods). This is illustrted in Fig. 3, which shows rurene single crystls ptterned into trnsistor rry. In most cses few crystls re found etween ech pir of source nd drin electrodes, ut in some cses just one rurene single crystl ridges the chnnel region (opticl microgrph in Fig. 3). One-step friction of lrge rrys of trnsistors with single crystl in the chnnel region hs until now een impossile to chieve with ny of the reported methods of singlecrystl field-effect trnsistor friction 1. More thn 99% of the devices with t lest one crystl ridging the drin nd source electrodes exhiited field effect, with the electricl chrcteristics of the highest-moility rurene device shown in Fig. 3. Overll, mesured moility vlues rnge from.1 to 2.4 cm 2 V 21 s 21. This lrge vriility my e prtly ttriuted to the mrked nisotropy of chrge trnsport in rurene 7 nd to differences in contct qulity t the dielectric/semiconductor nd electrode/semiconductor interfces. The crystls re le to mke contct ecuse the stmped OTS on oth Au nd consists of sprse pillrs tht do not fully cot the surfce. Moreover, some of the OTS stmped on Au ws found to evporte on heting under conditions similr to those used during crystl growth (Supplementry Fig. 19). The growing crystl itself lso seems to push some OTS pillrs outside the stmping field, therey leving visile outline of the peeled-off crystl on the sustrte (Supplementry Fig. 2); this effect increses the contct re etween the crystl nd the dielectric nd electrode surfces. But the clculted moilities my nevertheless underestimte the true moilities, ecuse it is still possile tht only portions of the ottom surfce of the crystl mke contct with the dielectric surfce. Nonetheless, rndom testing of 22 of the devices in the Pentcene PDMS stmp OTS film 5 μm (1) Print OTS film c Rurene (2) Remove stmp Printed OTS film d 1 μm (3) 1. Vcuum-sel sustrte Fullerene C 6 2. Crystl growth from vpour Single crystls 1 μm Figure 1 Ptterning of orgnic single crystls., Schemtic outline of the procedure used to grow orgnic single crystls on sustrtes tht hve een ptterned y microcontct printing. The printing uses PDMS stmps with relief fetures tht re inked with thick OTS film nd then pressed onto the sustrtes. To grow the ptterned single crystls, the ptterned sustrte is plced in glss tue with the orgnic source mteril, vcuumseled (.38 mm Hg), nd plced in temperture grdient furnce tue Nture Pulishing Group d, Ptterned single-crystl rrys of different orgnic semiconductor mterils. The dotted squre in ech imge indictes the size nd loction of one of the OTS-stmped domins, while the moleculr structure of the orgnic mteril used is shown next to the imge of its single-crystl rry., Pentcene (scnning electron microscope, SEM, imge; stmped domin size mm); c, rurene (SEM, mm); d, C 6 (opticl microgrph, mm).

3 NATURE Vol Decemer 26 rurene-sed trnsistor rry yielded n verge sturtion regime moility of, cm 2 V 21 s 21 with on/off rtios greter thn 1 7 (Supplementry Fig. 1). These chrcteristics re comprle to those of morphous silicon trnsistors nd high-performnce orgnic thin film trnsistors reported in the literture Pentcene singlecrystl trnsistors were similrly fricted using unpurified, sreceived pentcene source mteril, with the resultnt devices exhiiting moilities on the order of.3 cm 2 V 21 s 21 nd on/off rtios.1 5. The electricl chrcteristics of typicl pentcene device re displyed in Fig. 3c. Finlly, devices mde y ptterning the n-chnnel mterils C 6 nd TCNQ were found to exhiit moilities of.3 nd 1 24 cm 2 V 21 s 21, respectively. Our friction method cn generte not only discrete single-crystl trnsistors on rigid /Si sustrtes, ut lso flexile trnsistor rrys. The sic scheme for flexile single-crystl devices on polyimide sustrte nd its reliztion with rurene s the ctive mteril re shown in Fig. 4 (see lso Methods for detils). The chrcteristics Numer of nuclei μm 25 μm of selected plstic rurene trnsistor efore nd fter ending (stretching, ending direction cross the chnnel) re presented in Fig. 4. Moilities s high s.9 cm 2 V 21 s 21 nd on/off rtios of 1 4 (threshold voltge,1.5 V) hve een mesured in our est flexile rurene field-effect trnsistors, while our est moility for flexile pentcene field-effect trnsistor ws.1 cm 2 V 21 s 21 with on/off rtios of,1 3 (Supplementry Fig. 5). No significnt loss in performnce ws oserved when the devices were ent to rdius s smll s 6 mm, s found in ending experiments performed on four rndomly chosen devices tht ll exhiited similr ehviour. This demonstrtes tht the ptterned single-crystl trnsistors cn endure strenuous ending, nd therefore re potentilly useful for flexile electronics. Besides rurene, high vpour pressure mterils such s nthrcene nd tetrcene were lso successfully ptterned on flexile nd trnsprent poly(ethylene terephthlte ) (PET) sustrtes without degrding the plstic (Fig. 4). The present results clerly show tht the friction method we descrie here cn e used to control the nucletion loction nd nucletion density of moleculr single crystls. But for the method to e technologiclly relevnt, the orienttion nd lignment of the crystls lso need to e controlled, ecuse chrge trnsport in single crystls cn e highly nisotropic 7. Preliminry results from our lortory suggest tht this is possile y using comined nucletion/lignment lyer. Another chllenge is the need for etter understnding of the crystl growth mechnism in this system so s 5 5 μm 1 μm 2, 4, 6, 8, 1, Active re (μm 2 ) V G = 2 V V 25 2 V 4 V V DS = 6 V /2 I DS (ma 1/2 ) 1 μm 1 μm 2 μm Figure 2 Controlling pentcene crystl nucletion. The numer of crystls nucleted nd grown per stmped domin is function of the domin re., Plot of the numer of pentcene crystls in ech stmped domin s function of stmped domin re. The dt points show the verge crystl numer found for the four different stmp sizes used in the experiment. The error rs indicte the stndrd error of the men, otined from counting the nuclei in 24 stmping domins of ech size (N 5 24). The red line is liner fit of the experimentl dt, yielding nucletion density vlue of one pentcene crystl per 49 mm 2 (equivlent to stmping re of mm). Insets, opticl microgrphs of the four different stmp sizes used., Exmple of lrge-re rry of discrete pentcene single crystls grown on mm stmped OTS pttern. The imge on the left is n opticl microgrph of the rry, with the enlrged view of the indicted re shown s n SEM imge on the right. c V G = V 26 Nture Pulishing Group 2 V 4 V 6 V V DS = 6 V /2 I DS (ma 1/2 ) 1 μm Figure 3 Single-crystl trnsistor rrys on rigid sustrtes. Arrys of working single-crystl trnsistors re produced y printing films of OTS domins onto rrys of source drin electrodes, followed y growth of orgnic single crystls in the printed domins., Opticl microgrph of rrys of functionl single-crystl trnsistors. The electricl chrcteristics of typicl single-crystl trnsistors in the rrys, long with imges of the trnsistors, re shown in for rurene, nd in c for pentcene. V DS, drin source voltge; V G, gte voltge; I DS, drin source current. Chrcteristics re s follows: (middle pnel), moility (m) cm 2 V 21 s 21, on/off rtio,1 6, threshold voltge (V th ) V; c (middle pnel), m 5.2 cm 2 V 21 s 21, on/off rtio,1 6, V th V. 915

4 NATURE Vol Decemer 26 PVP dielectric Kpton polyimide 1 Source Drin V 2 2 V V 8 V 3 1 V Moility (V 1 s 1 ) Before After Ptterned moleculr crystls V DS = 6 V 4 Strin (%) Unent Bending rdius (mm) to optimize the electricl contct etween the crystls nd the dielectric lyer, s well s etween the crystls nd the electrodes. Of course, prcticl pplictions in lrge-re flexile electronics will lso require precise control of the growth process, to llow scling of the friction method to lrger res while chieving high device uniformity nd high device yield. METHODS Sustrte ptterning nd crystl growth. OTS printing solutions were prepred in regent grde toluene with concentrtions rnging from.1 to 1. M. Cotton pplictors were used to ink the PDMS stmps with the OTS solutions, nd n ir gun ws used to dry the stmps from excess solvent. The stmps were rought into contct with sustrtes for pproximtely 5 min. No rinsing or het tretment ws dministered to the OTS-ptterned sustrtes. To deposit the crystls, we used 16-mm-dimeter glss tue tht ws open t one end nd hd lredy 6 Au Bend t 6 mm After ending Figure 4 Flexile single-crystl trnsistor rrys., Digrm of the sic design for single-crystl trnsistor rrys on plstic sustrtes (top). The opticl microgrphs (ottom) show rurene trnsistor rry ttched to glss vil of dimeter 11.7 mm (left), nd nthrcene crystls ptterned on poly(ethylene terephthlte) (PET) sustrte nd fluorescing under n ultrviolet light source (right). Ptterned orgnic crystls were grown on flexile Kpton devices tht were tped onto pre-cut glss microscope slides with high-temperture polyimide tpe., Electricl chrcteristics of the single-crystl rrys. Left, the performnce of typicl flexile rurene single-crystl trnsistor. The middle nd right pnels illustrte the effect of device rry ending on device performnce. Middle, the trnsfer curves of flexile device ent t 6 mm ending rdius nd fter ending (tht is, ck in plnr geometry); right, plot of moility s function of the ending rdius (or strin percentge, which is indicted on the top xis). The green nd ornge curves in the middle pnel correspond to the green nd ornge dt points in the right pnel. The electricl chrcteristics of ll devices were first mesured in the plnr geometry, then repetedly in the ent geometry, nd finlly gin in the originl plnr geometry, similr to procedures used in ref Nture Pulishing Group een closed (y flme-seling) t the other. Semiconductor mteril ws plced inside the tue ner the closed end (,1 mg of source mteril used); the ptterned sustrte ws put onto NiCr wire clip nd plced inside the tue, severl centimetres wy from the source mteril. Susequently, the tue ws completely flme-seled under vcuum pressure of,.38 mm Hg using stndrd lortory vcuum pump. As n exmple of the procedure used, the pentcene source temperture is mintined t,26 uc nd the closest edge of the ptterned sustrte is positioned 2 cm wy (,25 uc) from the source zone. The nucletion zone of pentcene crystls extends to the fr edge of the smple 5 cm wy from the source (,22 uc). Next, the vcuum-seled tue is plced into temperture grdient sulimtion rector similr to the construction reported in ref. 16. Pentcene single crystls were grown in s little s 5 min with 5 mm stmps nd in,3 min using 1 mm stmps. Typicl source tempertures for pentcene re,26 uc. Growth tempertures for rurene nd C 6 were uc nd uc, respectively. Incresing the source temperture increses the rte of crystl growth, ut lso increses the distnce from the source to the crystl-forming region. Clirtion of mterils under controlled prmeters ws conducted to determine the exct distnce of crystl growth with respect to the source zone. Lrger-dimeter glss tues were used in order to fricte lrger-re ptterns. Orgnic source mterils were purified y temperture grdient sulimtion, ut in most cses, they were used without ny purifiction nd used s received. Device rry friction. Bottom-contct devices ( source drin electrode rrys, chnnel lengths 1, 2, 5, 1 mm) were defined y conventionl photolithogrphy (metl thickness: Cr, 1.5 nm; Au, 4 nm). Single-crystl trnsistors were fricted on conventionl sustrtes contining dielectric thickness of 3 nm on highly doped Si. A cpcitnce of 1 nf cm 22 ws used to clculte the field-effect moility of trnsistors on 3 nm dielectric, wheres cpcitnce of 1.9 nf cm 22 ws used for 1.5-mm-thick poly-4-vinylphenol (PVP, M w 5 2,) dielectric. For flexile trnsistors, dielectric lyer of PVP ws spin-coted (,2, r.p.m.) on 14-mm-thick Kpton (polyimide) sheets covered with 1 nm gold coting used for the gte electrode (Astrl Technology Unlimited). The dielectric solution ws prepred from 22 wt% PVP, nd 8 wt% poly(melmine-co-formldehyde), methylted (M w 5 511), dissolved in propylene glycol monomethyl ether cette (PGMEA) 27. The sustrtes were ked t 1 uc for 1 min then t 2 uc for 1 min to initite crosslinking. The source drin electrodes were fricted y therml evportion of Cr (1.5 nm) nd Au (5 nm) for flexile sustrtes. The W/L (W, chnnel width; L, chnnel length) for our highest moility rurene devices were,2 for conventionl sustrtes nd,4 for flexile polyimide devices. Ptterned orgnic crystls were grown on flexile Kpton devices tht were tped onto pre-cut glss microscope slides with high-temperture polyimide tpe. All devices were first mesured in the plnr geometry mode followed y severl ent geometry mesurements, nd finlly mesured in the originl plnr geometry, similr to procedures used in ref. 28. Received 6 July; ccepted 1 Novemer de Boer, R. W. I., Gershenson, M. E., Morpurgo, A. F. & Podzorov, V. Orgnic single-crystl field-effect trnsistors. Phys. Sttus Solidi 21, (24). 2. Briseno, A. L. et l. Ptterned growth of lrge oriented orgnic semiconductor single crystls on self-ssemled monolyer templtes. J. Am. Chem. Soc. 127, (25). 3. Huitem, H. E. A. et l. Plstic trnsistors in ctive-mtrix displys. Nture 414, 599 (21). 4. Moon, H. et l. Synthesis, crystl structure, nd trnsistor performnce of tetrcene derivtives. J. Am. Chem. Soc. 126, (24). 5. Podzorov, V. et l. Intrinsic chrge trnsport on the surfce of orgnic semiconductors. Phys. Rev. Lett. 93, 8662 (24). 6. Pope, M., Chrles, E. & Swenerg, C. E. Electronic Processes in Orgnic Crystls nd Polymers (Oxford Univ. Press, New York, 1999). 7. Sundr, V. C. et l. Elstomeric trnsistor stmps: Reversile proing of chrge trnsport in orgnic crystls. Science 33, (24). 8. Zeis, R. et l. Field effect studies on rurene nd impurities of rurene. Chem. Mter. 18, (26). 9. Steudel, S., Jnssen, D., Verlk, S., Genoe, J. & Heremns, P. Ptterned growth of pentcene. Appl. Phys. Lett. 85, (24). 1. De Vusser, S., Steudel, S., Myny, K., Genoe, J. & Heremns, P. Integrted shdow msk method for ptterning smll molecule orgnic semiconductors. Appl. Phys. Lett. 88, 1351 (26). 11. Aizenerg, J., Blck, A. J. & Whitesides, G. M. Controlling locl disorder in selfssemled monolyers y ptterning the topogrphy of their metllic supports. Nture 394, (1998). 12. Aizenerg, J., Blck, A. J. & Whitesides, G. M. Control of crystl nucletion y ptterned self-ssemled monolyers. Nture 398, (1999). 13. He, J. H. et l. Pttern nd feture designed growth of ZnO nnowire rrys for verticl devices. J. Phys. Chem. B 11, 5 53 (26).

5 NATURE Vol Decemer vn der Wilt, P. C., vn Dijk, B. D., Bertens, G. J., Ishihr, R. & Beenkker, C. I. M. Formtion of loction-controlled crystlline islnds using sustrte-emedded seeds in excimer-lser crystlliztion of silicon films. Appl. Phys. Lett. 79, (21). 15. Viks, R. et l. in Proc. Interntionl Electron Devices Meeting (IEEE Interntionl, 25). 16. Kloc, C., Simpkins, P. G., Siegrist, T. & Ludise, R. A. Physicl vpor growth of centimeter-sized crystls of lph-hexthiophene. J. Cryst. Growth 182, (1997). 17. Choi, H. Y., Kim, S. H. & Jng, J. Self-orgnized orgnic thin-film trnsistors on plstic. Adv. Mter. 16, (24). 18. Ruiz, R. et l. Pentcene thin film growth. Chem. Mter. 16, (24). 19. Heringdorf, F., Reuter, M. C. & Tromp, R. M. Growth dynmics of pentcene thin films. Nture 412, (21). 2. Mrkov, I. V. Crystl Growth for Beginners (World Scientific, Singpore, 23). 21. Venles, J. A., Spiller, G. D. T. & Hnucken, M. Nucletion nd growth of thin films. Rep. Prog. Phys. 47, (1984). 22. Grnsy, L., Borzsonyi, T. & Puszti, T. Nucletion nd ulk crystlliztion in inry phse field theory. Phys. Rev. Lett. 88, 2615 (22). 23. Grnsy, L. et l. Phse field theory of crystl nucletion nd polycrystlline growth: A review. J. Mter. Res. 21, (26). 24. Verlk, S., Steudel, S., Heremns, P., Jnssen, D. & Deleuze, M. S. Nucletion of orgnic semiconductors on inert sustrtes. Phys. Rev. B 68, (23). 25. Kelley, T. W. et l. Recent progress in orgnic electronics: Mterils, devices, nd processes. Chem. Mter. 16, (24). 26. Kluk, H., Gundlch, D. J., Nichols, J. A. & Jckson, T. N. Pentcene orgnic thinfilm trnsistors for circuit nd disply pplictions. IEEE Trns. Electron Devices 46, (1999). 27. Kluk, H. et l. High-moility polymer gte dielectric pentcene thin film trnsistors. J. Appl. Phys. 92, (22). 28. Briseno, A. L. et l. High-performnce orgnic single-crystl trnsistors on flexile sustrtes. Adv. Mter. 18, (26). Supplementry Informtion is linked to the online version of the pper t Acknowledgements A.L.B. cknowledges Bell Ls Grdute Reserch Fellowship. A.L.B., F.W., R.J.T. nd Y.Y. cknowledge finncil support from the Air Force Office of Scientific Reserch (AFOSR). S.C.B.M. cknowledges finncil support from the Deutsche Forschungsgemeinschft, nd Z.B. cknowledges prtil support from the Stnford Center for Polymeric Interfces nd Mcromoleculr Assemlies (NSF-Center MRSEC), the Stnford School of Engineering, nd Slon Reserch Fellowship. Author Contriutions A.L.B. performed single-crystl ptterning on sustrtes nd FET devices, mesurements on FET devices, nd wrote most of the mnuscript. S.C.B.M. elucidted the growth mechnism, performed AFM mesurements, nd wrote prts of the mnuscript. M.M.L. ssisted in smple preprtion nd ssisted in device mesurements nd clcultions. S.L. ssisted in crystl ptterning, device preprtion, nd performed SEM mesurements. R.J.T. ssisted in flexile device preprtion, mesurements nd clcultions. C.R. designed nd fricted the trnsistor rry devices nd PDMS stmp msters vi lithogrphy. M.E.R. ssisted in erly experiments nd purified some of the orgnic source mterils. Y.Y. provided use of lortory spce nd instruments. F.W. provided feedck nd suggestions on experiments. Z.B. conceptulized nd directed the reserch project. All uthors discussed the results nd commented on the mnuscript. Author Informtion Reprints nd permissions informtion is ville t The uthors declre no competing finncil interests. Correspondence nd requests for mterils should e ddressed to Z.B. (zo@chemeng.stnford.edu). 26 Nture Pulishing Group 917