High temperature UV photodetectors based on the negative differential resistance effect of WO3/diamond PN junctions

Abstract

A positive-negative (PN) junction tunneling diode ultraviolet (UV) photodetector of p-boron-doped diamond (BDD)/n-WO3 nanorods (NRs) with broad-band and good thermal stability was fabricated using heavily boron-doped degenerate semiconductor diamond (BDD) as a substrate. The operating temperature of the p-BDD/n-WO3 photodetector was increased to 300 °C through the negative differential resistance effect, benefiting from the excellent properties of diamond such as an increase in the concentration of boron atoms, a wideband gap (∼5.5 eV), and high thermal conductivity. In particular, the devices exhibited a negative differential resistance phenomenon in the range of 30–240 °C, accompanied by a rapid increase in photocurrent values and the phenomenon disappeared as the temperature rises to 300 °C. Moreover, a quick response speed (tr1 = 1.2 s), a high photocurrent (0.11 A at 5 V), a good rectification ratio (1.81), and a photo to dark current ratio (0.15) can be demonstrated in the p-BDD/n-WO3 NRs photodetector at 300 °C, indicating its excellent thermal stability. This work provides an effective way method for realizing UV photodetectors based on the negative differential resistance effect and reclaims the potential application of p-BDD/n-WO3 in high temperature semiconductor optoelectronic devices.