Performance analysis of vertical channel organic thin film transistors through 2-D device simulation

Abstract

This research paper puts forward the electrical behavior of vertical channel organic thin film transistors (V-OTFTs) using organic module of Atlas 2-D numerical device simulator. The electrical characteristics and performance parameters of pentacene based V-OTFT is analyzed. The devices are compared for different line spacing and line width while taking same structural dimensions and electrical properties. The conventional organic thin film transistors (C-OTFT) offers merits of low cost and low temperature fabrication, however, C-OTFTs with long channel length (L) undergo low mobility, low speed and high bias voltage of operation. It is extremely challenging to achieve short channel length in C-OTFTs by using a low cost shadow masking technique. To fulfil this gap, vertical channel structure is investigated for the organic thin film transistor that has proven its potential for fabricating smaller length OTFTs. A vertical channel structure consists of different thin film layers that include three layers of the source, drain and gate in combination with two semiconductor layers. The results observed maximum current I dmax is 24.20, 18.37 and 32.70μA for device 1, 2 and 3 respectively. The 35% and 78% higher current observed for device 3 in comparison to device 1 and device 2 with increase in line-width of 28% w.r.t. to device 1 and 2. Organic-electronics is not a technology competing with inorganic electronics (silicon based devices), but intends for novel-applications that are not feasible or are too costly with MOS transistors.