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Study On The Electrode Injection Implantation Effect Of Pentacene Based On Organic Thin Film Transistor

Posted on:2019-05-14Degree:MasterType:Thesis
Country:ChinaCandidate:F JiangFull Text:PDF
GTID:2428330566488629Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
Organic Thin Film Transistor?OTFT?materials have a wide range of sources,are used in flexible substrates and can be mass-produced and its simple production process,and it have become one of the research hotspots at home and abroad.The quality of met-al-semiconductor interface contact is one of the key factors affecting the performance of OTFT devices.Therefore,this paper focuses on the research of pentacene-based OTFT devices.Electrode injection performance.Based on the method of controlling the contact barrier of the metal-pentacene interface,the device electrode implantation effect is im-proved,and the influence of the electrode modification material and the single-electrode modification layer structure on the contact barrier is investigated.Firstly,the matching effects of Au,Ag,Cu and MoO3 energy levels are investigated.It is found that when Cu and MoO3 match,the electrode-semiconductor contact barrier is the smallest,which is most conducive to the hole injection of the electrode.Due to the different transport effects of carriers on the source and drain electrodes of OTFTs,the ef-fects of MoO3 as a single electrode modification layer and a bipolar modification layer on the device performance are studied.Secondly,the preparation of OTFT devices with different thicknesses of LiF elec-trode modified layer,OTFT devices with LiF thickness of 4 nm have the best overall per-formance.In addition,the best thickness LiF as a two-electrode modified layer and the drain modified layer device performance after increasing the LiF thickness were compared and analyzed.When LiF is used as OTFT electrode modification layer to optimize device performance,the main mechanism of action is different.As the drain electrode barrier layer is to use its own insulation properties,increase the drain Cu-semiconductor contact potential barrier,reduce the leakage current,so that the device switching ratio increased by an order of magnitude.Thirdly,due to the variety of sulfur and copper compounds,the valence state is not fixed,and CuS is easily decomposed into simple copper and elemental sulfur at high tem-peratures,CuS is considered as an electrode modification layer to study the effect of CuS compound electrode on the carrier injection effect of the device.The Ag/CuS and Cu/CuS composite electrode OTFT devices were prepared.The performance parameters of the two devices were compared and analyzed.It is found that the Cu/CuS composite electrode has a higher electrode implantation effect.Compared with standard parts,the carrier mobility increased by 1.5 times and the switching ratio increased by 5.2 times.The CuS composite source electrode device is prepared.When Cu/CuS is used as the source modification layer,the source-drain current and the mobility did not change much,but the switching ratio of the device is reduced.This shows that the Cu/CuS composite source electrode device structure is not conducive to the optimization of the overall performance of the OTFT de-vice.Finally,try to prepare Cu/Al alloy electrodes and explore the effect of Cu/Al alloy electrodes on the performance of OTFT devices.It is found that the Cu/Al alloy electrode with a work function between copper and aluminum can improve the OTFT carrier transport,but its mechanism of action is not the regulation of MS interface contact energy levels.When the Cu/Al alloy is used as the drain electrode of the OTFT,the height of the barrier at the MS interface can be significantly increased and the carrier transport can be impeded.Compared with a single metal electrode standard,the switching ratio is increased by an order of magnitude.
Keywords/Search Tags:organic thin film transistor, pentacene, single electrode modification layer, alloy electrode, current switching ratio
PDF Full Text Request
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