An ultra-fast two-terminal organic phototransistor with vertical topology for information technologies

Abstract

An organic two-terminal phototransistor structure for information technology has been designed, fabricated, and demonstrated. The device comprises a resistive random access memory (RRAM) in tandem with an organic solar cell (OSC). The transistor effect is realized by the functional integration of both individual devices; i.e., the photocurrent produced by the OSC is manipulated through the switchable RRAM. Compared with conventional phototransistors, our design possesses several intriguing features, including ultra-fast photoresponse time, controllable photocurrent, and solution processable active layers. Most importantly, these operational properties are achievable with only two vertically sandwiched electrodes, which are beneficial for high speed optical communication, circuit miniaturization, and energy saving. These unique features make it a good candidate for implementation in optical communication with diverse applications such as Li-Fi technology and security encryption.