Narrow‐Band QD‐Enhanced PIN Metal‐Oxide Heterostructure Phototransistor with the Assistance of Printing Processes

Abstract Infrared (IR) phototransistors are important building blocks for the true integration of flat‐panel optoelectronic detectors. Although significant progress is made in obtaining an InGaZnO active layer with IR response, the utilization of a high‐performance detector still has many challenges due to low efficiency, high power consumption, and lagging detection speed. Herein, a positive‐intrinsic‐negative (PIN) heterostructure phototransistor directly modulating the charges' transfer barrier with low power consumption (1 nW), high efficiency (EQE > 700%), a 200 Hz detecting bandwidth, and high detectivity (1 × 10¹¹ cm Hz^1/2 W⁻¹) at an IR wavelength (1.5 µm in the high‐frequency circumstance) is demonstrated. These excellent sensing properties of the PIN phototransistor, together with its advantages of low power consumption and versatility, make the use of a heterostructure a powerful strategy for the development of on‐chip optoelectronic detectors.