Abstract
As the carrier behavior is crucial to the photoelectric conversion process, the charge-carrier engineering could provide feasible strategy for high-performance photodetector (PD). Herein, self-powered ultraviolet PDs were constructed on VOx/Ga2O3 (VGO) heterojunctions by adopting the solution processed VOx films as hole transport layer (HTL). Treated with different annealing ambients, the HTL demonstrated changeable conductivities due to the regulated crystallinities, phase structures and chemical valences, which further exerted influences on the VGO PDs inducing controllable photodetection properties. With effective hole transportation, low valence band barrier and large built-in field, the modulated VGO PDs achieved enhanced self-powered photodetection performance with photo-to-dark current ratio of 1.08 × 108, on/off ratio of 1.23 × 106, rejection ration (R245/R400) of 3.12 × 104, responsivity of 28.9 mA/W and detectivity of 1.13 × 1014 Jones as well as rise/decay time of 57/74 ms. In consideration of the carrier-transport problems are commonly ubiquitous and particularly vital, our proposed HTL engineering method could open the high-performance route for self-powered ultraviolet PDs.
NSTL
Elsevier