Enhanced solar-blind deep UV photodetectors based on solution-processed p-MnO quantum dots and n-GaN p–n junction-structure

Obtaining p-type wide-bandgap semiconductors with a bandgap >3.5 eV is still challenging. Here, p–n junction devices based on (≥4 eV) MnO quantum dots (QDs) and n-type Si-doped GaN are fabricated. The p-MnO QDs synthesized by cost-effective femtosecond laser ablation in liquid. A simple spray-coating method used for fabricating the p-MnO/n-GaN-based solar-blind deep UV (DUV) photodetector. X-ray diffraction, transmission electron microscopy, Raman spectroscopy reveal QD crystal structure. photoelectron microscopy analysis reveals good band alignment between n-GaN, demonstrating (type-II) staggered heterojunction-based device. Electrical photocurrent measurements show high response low dark current, while superior photo-responsivity (∼2530 mA/W) achieved, along self-powered visible-blind characteristics (265 nm cutoff), high-performance DUV device detection limit light level applications. This study provides insights into potential of III-nitride devices.