Asymmetrical Schottky Junction Built by Metal/Conducting Polymer Targeting Efficient Flexible Direct Current Tribovoltaic Generator

Abstract

Direct current (DC) from mechanical energy built on the tribovoltaic effect is promising for the development of self‐powered flexible electronics. A semiconductor triboelectric generator is one of the optimized solutions for DC output. However, it remains underutilized because of its low output power and insufficient insight into the fundamental principles of charge generation and transport at dynamic interfaces. Herein, a flexible fabric‐based DC generator that relies on a metal–semiconducting polymer interface constructed by an asymmetric Schottky junction between a poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS)‐coated fabric and an aluminum (Al) foil is reported. The dependence of the electrical output performance of the device on the doping carrier concentration using different types of PEDOT:PSS to modulate the Schottky barrier height, validating both the work function and conductivity of the triboelectric material, which plays a fundamental role in DC generation, is explored. A large work function difference is required to create a high built‐in electric field for efficient separation of electron–hole pairs. Decent conductivity also fulfills an integral role in the innate carrier‐transport capability. Accordingly, an open‐circuit voltage (Voc) of 800 mV, a short‐circuit current (Isc) of 80 μA, and a power density of 6.7 mW cm−2 are yielded simultaneously.