Frequency response characteristics of pyroelectric effect in p-n junction UV detectors

By coupling pyroelectric effect and photoelectric effect, pyro-phototronic effect is proposed to effectively modulate photon response characteristics of the detector with p-n junction. Here, tuning role of chopper frequency on pyroelectric effect in p-n junction is revealed by demonstrating the dynamic performances of pyrophototronic effect based UV photodetectors (PDs) under different power densities and different bias voltages. Different from the traditional pyroelectric detectors without p-n junction, the pyro-phototronic effect based PDs possess the optimal response frequency that is strong dependent on the stimuli power density and the external bias voltage. With the power density increasing from 7.9 x 10(-5) to 1.5 x 10(-3) Wcm(-2), the optimal chopper frequency of the self-powered PD increases from 50 Hz to 200 Hz. By changing the bias voltages, the transient currents have a group of maximal values for different chopper frequencies at a same voltage of -0.2 V when the detector is illuminated by UV light with a power density of 1.8 x 10(-2) Wcm(-2). The results present the fundamental working characteristics of the pyro-phototronic effect based PD and provide guidance for its future applications in IR imaging, fast detecting and smart optoelectronic systems.