Kim Jiye, Lee So Hee, Kim Haekyoung, Kim Se Hyun, Park Chan Eon
†POSTECH Organic Electronics Laboratory, Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk 790-784, Korea.
§School of Materials Science and Engineering, Yeungnam University, 280 Daehak-Ro, Gyungsan, Gyeongbuk 712-749, Korea.
ACS Appl Mater Interfaces. 2015 Jul 8;7(26):14272-8. doi: 10.1021/acsami.5b02610. Epub 2015 Jun 26.
We successfully fabricated high performance bottom-contact organic field-effect transistors (OFETs) using silver nanowire (AgNW) network electrodes by spray deposition. The synthesized AgNWs have the dimensions of 40-80 nm in diameter and 30-80 μm in length and are randomly distributed and interconnected to form a 3D hollow framework. The AgNWs networks, deposited by spray coating, yield an average optical transmittance of up to 88% and a sheet resistance as low as 10 ohm/sq. For using AgNWs as source/drain electrodes of OFETs with a bottom-contact configuration, the large contact resistance at the AgNWs/organic channel remains a critical issue for charge injection. To enhance charge injection, we fabricate semiconductor crystals on the AgNW using an adsorbed residual poly(N-vinylpyrrolidone) layer. The resulting bottom-contact OFETs exhibit high mobility up to 1.02 cm(2)/(V s) and are similar to that of the top-contact Au electrodes OFETs with low contact resistance. A morphological study shows that the pentacene crystals coalesced to form continuous morphology on the nanowires and are highly interconnected with those on the channel. These features contribute to efficient charge injection and encourage the improvement of the bottom-contact device performance. Furthermore, the large contact area of individual AgNWs spreading out to the channel at the edge of the electrode also improves device performance.
我们通过喷雾沉积法成功制备了基于银纳米线（AgNW）网络电极的高性能底接触有机场效应晶体管（OFET）。合成的银纳米线直径为40 - 80纳米，长度为30 - 80微米，随机分布并相互连接形成三维中空框架。通过喷雾涂层沉积的银纳米线网络平均光学透过率高达88%，方块电阻低至10欧姆/平方。对于将银纳米线用作具有底接触配置的OFET的源极/漏极电极而言，银纳米线/有机沟道处的大接触电阻仍然是电荷注入的关键问题。为了增强电荷注入，我们利用吸附的残余聚（N - 乙烯基吡咯烷酮）层在银纳米线上制备半导体晶体。由此得到的底接触OFET表现出高达1.02厘米²/（伏·秒）的高迁移率，与具有低接触电阻的顶接触金电极OFET相似。形态学研究表明，并五苯晶体在纳米线上聚结形成连续形态，并且与沟道上的晶体高度互连。这些特性有助于高效电荷注入，并促进底接触器件性能的提升。此外，单个银纳米线在电极边缘向沟道扩展的大接触面积也改善了器件性能。
