Bi2O2Se/Au-Based Schottky Phototransistor With Fast Response and Ultrahigh Responsivity

Bi
₂
O
₂
Se has attracted a great deal of attention in optoelectronic applications due to its high mobility, sensitivity and long-term ambient stability. Here, we fabricate high-performance Bi
₂
O
₂
Se phototransistors with a maximum photoresponsivity of 27592 A/W under 532 nm illumination using Au contacts, where two back-to-back Schottky barriers (SBs) are formed, leading to photovoltaic effect. SB formation is believed to be attributed as the main contributing factor to the photoresponse of this metal semiconductor structure with a fastest response time of ~24μs. Our work demonstrates that Bi
₂
O
₂
Se/Au-based phototransistors have promising potential in photodetection applications.