Avalanche-like breakdown behavior of copolymer organic semiconductor-based Schottky junction structure

Abstract

Organic field-effect transistors have demonstrated their outstanding off-state breakdown performance. Yet, the physical nature of their electric breakdown remains unexplored. In this paper, by employing a lateral back-to-back Schottky junction composed of diketopyrrolopyrrole-based conjugated copolymer (DPPT-TT) and Au metal, the breakdown performance of copolymer organic semiconductor (OSC) is experimentally demonstrated. The nondestructive/repeatable breakdown behavior and positive coefficient between temperature and breakdown voltage indicate that the avalanche-like breakdown mechanism plays a dominant role in determining the breakdown characteristic of OSC-based power devices. Based on the lateral back-to-back Schottky junction, a characterization method of key breakdown parameters is proposed. The extracted critical electric field (EC) of DPPT-TT is up to 5.0 MV/cm, which is more than one order of magnitude higher than that of single-crystal silicon. Despite the fact that copolymer OSCs are narrow bandgap semiconductors, they still deliver excellent breakdown performance, making them a promising building block for future power electronics.