BTO/GaN heterostructure based on Schottky junction for high-temperature selective ultra-violet photo detection

Abstract

Ferroelectric/semiconductor heterostructures have attracted great interest for future optoelectronic and electronic devices due to ferroelectric polarization induced interfacial charge coupling at the junction. Here, we report on the fabrication of GaN/BaTiO3 (GaN/BTO) heterostructure based Schottky junction on c-sapphire using pulsed laser deposition and its performance in UV detection. The Schottky-type BTO/GaN heterojunction for high temperature selective ultraviolet photo detection is demonstrated ranging from 313 to 423 K. The temperature-dependent parameters such as responsivity (Rλ), sensitivity (S), specific detectivity (D*), and barrier height (φb) and ideality factor (η) of the device have been quantified. Calculated parameters are systematically compared with the effect of dark and UV light. The responsivity increases with respect to temperature up to 413 K and then decrease. The highest UV (λ = 360 nm) responsivity is found to be 45.54 and 45.21 A W−1, at temperature 393 and 413 K respectively under +5 V bias. The Schottky barrier height of BTO/GaN heterojunction increased with increasing temperature in presence of dark as well as UV light while ideality factor decrease in both the cases. Overall, the efficiency of BTO/GaN device is optimized at 413 K. We have observed high sensitivity of BTO/GaN device as compared to GaN device with respect to applied bias.