Toward both p- and n-doping of hexagonal boron nitride using sub-bandgap illumination

Abstract

Giant room temperature persistent photoconductivity in hexagonal boron nitride under UVC irradiation has been demonstrated. Scanning lasers dots on sample surface at two different wavelengths (213 and 266 nm) have been used to induce such effect, the former being more efficient. Conductivity has been increased by 6 orders of magnitude upon illumination. Such increase persists significantly for at least 6 months. Decrease of photoinduced current has been shown to be 10% more important for samples irradiated under vacuum than for those irradiated under atmospheric pressure. Type of photoinduced carriers were investigated using p-hBN/n-AlGaN junctions through C/V measurements. P-type carriers are believed to be generated by 213 nm illumination whereas 266 nm laser is supposed to trigger n-type carriers.