Fast-response PN-photodetector based on V2O5-nanorods/macroporous Si heterojunction

Abstract

The development of optoelectronic devices such as high-performance photodetectors is still needed. In this study, a heterojunction photodetector was fabricated by growing vanadium pentoxide nanorods (V2O5-NRs) on macroporous silicon (MacroPSi) using thermal evaporation technology. This was followed by 60 minutes of annealing at 550 °C in an oxygen-free environment. X-ray diffraction, field emission scanning electron microscopy, and ultraviolet-visible-near infrared spectroscopy were used to investigate the structural, morphological, and optical features of the produced V2O5-NRs. The performance of the photodetectors is measured by the (I-V) characteristics in the dark and in the light using two point probes connected to Keithley 6487 and a green LED (532 nm, 8 mW/cm2) with -5 V to +5 V for the baise voltage. The nonlinear I-V curve reveals the existence of Schottky barriers at the interfaces of the n-type V2O5-NRs and the MacroPSi substrate as the current runs vertically through the device. These curves are used to determine the photodetector's sensitivity and resposivity. The current device, V2O5-NRs/MacroPSi, demonstrated good values of sensitivity and responsivity equal to 20.8 and 5.2 A/W under 532 nm (8 mW/cm2) at 3 and 5 V, respectively. In addition, the rise and fall durations of the photodetector under the same light source at 5 V were estimated to be 0.24 and 0.22 seconds, respectively. In light of the obtained results, it's clear that the produced V2O5-NRs/MacroPSi heterostructure is a good contender for excellent performance as a photodetector in commercial photoelectronic device applications.