Influence of Temperature on Photodetection Properties of Honeycomb-like GaN Nanostructures

Broadband photodetectors operable under harsh temperature conditions are crucial optoelectronic components to support ongoing and futuristic technological advancement. Conventional photodetectors are limited to room temperature operation due to the thermal instability of semiconductors under harsh conditions and incapable of covering the ultraviolet (UV) spectrum due to narrow bandgap properties. Gallium nitride (GaN) is a wide bandgap and thermally stable semiconductor, ideal for addressing the abovementioned limitations. Here, epitaxial honeycomb nanostructured GaN film is grown via a plasma-assisted molecular beam epitaxy system and deployed for stable broadband photodetectors, which can be operated from −75 to 250 °C. Further, spectral response is investigated for a broad spectrum from UV (280 nm) to near-infrared (850 nm) region. It displays a peak responsivity at 365 nm associated to the bandgap energy of GaN. Fabricated photodetectors with honeycomb-like nanostructures drive peak responsivity and external quantum efficiency of 2.41 × 106 AW−1 and 8.18 × 108%, respectively, when illuminated at a power density of 1 mWcm−2 and 365 nm wavelength source under 1 V bias. Temperature-correlated spectral response presents a quenching of responsivity at higher temperatures in visible spectrum associated with the thermal quenching of defect states. The thermally stable and efficient broadband photodetector based on honeycomb-like nanostructured GaN is promising for the combustion industry, arctic science, and space explorations.