光电功能lecture-ofet xu mingsheng有机场效应晶体管薄膜

OrganicField-EffectTransistorsOrganicThinFilmTransistorsDominatedbyinorganicSiliconandWellHighlyMemory

300Solar

®45nm,sixToday’schipscontainmillionsoftransistorsandareusedineverythingfrom andcomputerstocarandnes Adevicecomposedofsemiconductormaterialsthatamplifiersasignaloropensorclosecircuit.Avoltageappliedbetweenthegateandsourcecontrolsthecurrentflowingbetweenthesourceanddrain Fieldeffecttransistoractsasavalveor tonesinTransistor1948-POINTCONTACT1951-GROWNJUNCTION1952-ALLOYJUNCTION1952-ZONEMELTINGAND1955-DIFFUSED-BASE Firsttransistor1957-OXIDE1960 1960-MOS1961-INTEGRATED

1941vacuumtubeusedforephone1948thepoint-contacttransistorwasintroduced(June30)totheworld,sixmonthsafterits1955transistorwhichrecedvacuumtubesinnetworkcommunicationsequipment;1957diffusedbasehighfrequencybroadband1967microchip,usedtoproducethetonesinatouch-toneephoneset,containedtwotransistors;1997aLucent digitalsignalprocessorchipusedinmodemsandcellularcommunicationsOrganictransistorsaretransistorthatuseorganicmoleculesratherthansiliconfortheiractivematerial.Thisactivematerialscanbecomposedofawidevarietyofmolecules. Lower-costdepositionprocesssuchasspinLowermobilityandswitchingspeedscomparedtosiliconwafers（低的迁移率 vertical Usingshadowmasktosource/drain

Channellength>10patiblewithlargescalefabricationandintegration. KazuhiroKudo.etal.,Adv.Mater.19,525 Light-emittingfieldeffect层薄膜(APL92,183304(2008))磷光材料(Adv.Mater.21,4951 carbonnanotubeenabledverticalfieldeffecttransistor(CN-Vg=0,relativelysmallIdsduetolowchargeconcentrationandhigh Vg<0,positivechargeinducedinOSC adjacenttothegatedielectricp-channel),thechargecanbeinjectedandextractedbyVdsiftheEFisclosetotheHOMO.（p-型）Vg>0,negativechargedinducedinOSCadjacenttothegatedielectricn-channel),thechargecanbeinjectedandextractedbyVdsiftheEFisclosetotheLUMO.（n-型） IdDrainCurrent（沟道电流）LChannellength（沟道长度）Startofsaturation Vd>W--

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Vg>

Output(Ids-Vds)

ON=conductionchannelThechargeinthechannelismodulatedbyadjustingVg,sothatthedevicebehavesasa OFF=Noconduction GatevoltageAFETisbasicallyacapacitor,whereoneteisconstitutedbythegateelectrode,andtheotheronebythesemiconductorfilm.WhenavoltageVgisappliedbetweensourceandgate,majoritycarriersaccumulateattheinsulator-semiconductorinterface,leadingtotheformationofaconductionchannelbetweensourceandApotentialsignalVgistransformedinacurrentsignal Transfer(Ids-Vg)

Fieldeffectmobility(μ)WCslope i ThresholdvoltaeVTh)On/Offcurrentratio(Ion/Ioff) （小分子与大分子Ket为电荷转移率（chargetransfer等子变形有关（分子内自由能、分子刚柔性以及共轭长度等有关 对主链进行修饰（取代基、功能基团 对主链进行修饰（取代基、功能基团），改善分子间的 domalongtheconjugate 并苯环多寡：(1)0.02(单晶(2)0.1(薄膜)2.4,(3)1~40,(4)4.28(定，合 ),(5)1.3,4.3(对称性取代，导致更紧密的分子堆砌)周围取代基，导致共面电子堆积：(6)15-40(7)1.6(8)1.7(9)9.011 （沿b和a轴的迁移率分别为15.4和4.4Science303,1644 Tetrathiafulvalenesand2DTetrathiafulvalenes(TTFs，四硫富瓦烯and2Dshapedmolecules(迁移率大于1.0cm2/Vs)1.2 3.65cm2/Vs(溶 10 Shallowsquare-pyramidstructure(浅的平面-金字塔)withtheoxygenatomoutoftheconjugated O2H2O等扩散。（2）引入强的吸电子基如chlorationcyanogroup等降低LUMO能级（低于环境的O2H2O的LUMO） 如同前面的p-OFET半导体，设计extended-4.56core-expandedPDIandNDI 的 尽管大分子可以采用溶液法

，然而，目前大分子 结构-性能的理解不透切，很难用于指导分子设计与合成 1990s,Regioregularpoly(3-hexylthiophene)(P3HT)的迁移率：0.1cm2/Vs，但其离化势较低（IP:4.8eV），导致稳定性差。设计分eV，迁移率：0.2cm2/Vs ，迁移率一般为0.1–0.7cm2/Vs。，

Nat.Mater.5,328 (alkyl-substitutedthienylenevinylene）提高材料的可 液 packingmode)packingmode)以及分子间的相互作用影响很大。对于改善溶解膨大的枝化偏链（bulkybranchedsidechains）的体积大，会增（迁移率） LargeAromaticCorePolymers (a)Cartoonrepresentationofconjugatedpolymerfilm,anditsthreepossiblechargetransportpathways.(b)Traditionalpolymercontainsoneortwoalkylchainsoneachunit.Sterichindrancemayexistwhenpolymersarestackedwitheachother(blackcircle).(c)Moleculardockingstrategytoavoidsterichindranceandimprovetheinterpolymerπ−πinction.Thecartoonrepresentationofcopolymerswithdifferentsymmetriesandtheirfilmpackings;(d)polymerswithcentrosymmetricdonorsand(e)polymerswithaxisymmetricdonors.

InorganicSiMOSFETswithshortchannellengths(L，短沟道)aredesirableforintegrateddigitallogiccircuits（集成电路）astheyincreasebothfunctionality（功能化）andclockspeed（比如主频）byvirtueofthefactthatbothpackingdensity(#/area)andlinearregimetheswitchingspeed,cut-offfrequency(f)scale,approximayas1/L2AreaL2PackingDensityf=Channelscale Small(ex:P3HT,F8T2)(ex:

Metal(ex:Au, MaterialsTFTChemicalTreatmentondielectricfilmsurface(silanelayerpretreatment,SAMsthiol-basedchemicalmodifiedcontact)Organiclayerdeposition(i)vacuumevaporation(ii)spincoating,solutioncasting,printingControllingthedepositionparameters(aging,depositionrate,annealprocess,solventquality,channellength,channeldimension,depositionthickness,solventevaporationtemperature) NointerfacebarrierwiththeactiveNometalHighcarrierinjection,lowMainlyusedasS/Delectrodesduetoitshighworkfunction(5.1eV)andlowinjectionbarrier ndipole Self-AssemblyMonolayerHydrophilictohydrophobic Self-AssemblyMonolayerAdv.Funct.Mater.15,77 bis-(triisopropylsilylethynyl)(TIPS)ChargeChargecarriermobilityisdependentonmolecularorderwithinthesemiconductingthinfilm. EnhancementonPerformanceof Chemicalsurfacetreatmentondielectricfilmsurfaceorelectrode(SAMssilanelayerpretreatment, smatreatment) ModifytheTFTstructure(bottomcontactortopcontact)Controltheprocessing(depositionrate,