Study of temperature dependent behavior of h-BN nanoflakes based deep UV photodetector

Abstract

Here we report on a robust deep ultraviolet (UV) photodetector based on hexagonal-boron nitride (h-BN) flakes. Metal-semiconductor-metal (MSM) photodetector was fabricated on mechanically exfoliated multilayered h-BN flake using high work function metal platinum (Pt). In this way, Schottky barrier height of 0.85 eV and ideality factor of 1.01 was obtained. The photocurrent at 205 nm was found to be 10 times higher than the dark current. The photodetector exhibited a responsivity of 5.2 mA/W at 10 V with incident power density of only 44.6 μW/cm2. A stable temporal response was observed by repeatedly switching on and off the incident light. The robustness of the photodetector was tested by varying the temperature from room temperature (RT) to 200 °C. Responsivity of 32 mA/W and photo to dark current ratio (PDCR) of 0.35 was obtained at 10 V, indicating good thermal stability of the photodetector.