In organic field effect transistors (OFETs), the accumulation channel for charge transport occurs within few layers on the top of gate dielectric. However this is the most poorly known parameter in OFETs, as it is extremely difficult to determine the charge accumulation thickness experimentally in unipolar OFETs. With the main objective to determine the thickness of accumulation channel, we have fabricated heterojunction OFETs using donor and acceptor organic semiconductors with similar (CuPc & F 16 CuPc) and dissimilar (pentacene & F 16 CuPc) molecular structure. The transistor characteristics of OFETs based on the organic heterojunction of similar and dissimilar molecular structure changed from unipolar transport (normally off) to normally on or unipolar to ambipolar transport by varying the bottom layer thickness and deposition order of organic molecules in the heterojunction. In normally off transistors, no conducting channel exist at zero gate bias...

中文翻译：

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由分子结构相似和相异的供体和受体有机半导体的异质结确定的累积沟道厚度的研究

在有机场效应晶体管（OFET）中，用于电荷传输的累积通道出现在栅极电介质顶部的几层内。然而，这是在OFET中最不为人知的参数，因为通过实验确定单极OFET中的电荷积累厚度非常困难。为了确定累积通道的厚度，主要目的是使用具有相似（CuPc和F 16 CuPc）和不相似（并五苯和F 16 CuPc）分子结构的施主和受主有机半导体制造异质结OFET。通过改变异质结中有机分子的底层厚度和沉积顺序，基于相似和不相似分子结构的有机异质结的OFET的晶体管特性从单极传输（常关）变为正常导通或单极至双极传输。在常关晶体管中，在零栅极偏置下不存在导电沟道。