Preparation of n-Ga2O3/p-GaAs Heterojunction Solar-blind UV Photodetectors
Ga2O3 thin films were deposited on p-GaAs(100)substrates by metal-organic chemical vapor deposition(MOCVD)process for the preparation of n-Ga2O3/p-GaAs heterojunction solar-blind UV photodetectors(PDs).The surface morphology and crystal quality of Ga2O3 thin films were measured and analyzed by X-ray diffractometer,atom-ic force microscope,and field emission scanning electron microscope.The results showed that the Ga2O3 thin films exhibited a single crystal orientation,with a flat surface and Volmer-Weber mode epitaxy.The characterization indi-cated that the n-Ga2O3/p-GaAs heterojunction detector exhibited an obvious rectification characteristic.The device achieves a photo-dark current ratio of more than 3.0×104,a responsivity of 7.0 A/W,an external quantum efficien-cy of 3412%,and a detectivity of 4.6×1013 Jones under 5 V reverse bias and UV(254 nm)illumination.The device structure was simulated using TCAD software,obtaining the electric field distribution and band structure inside the device,and the working principle of the device was analyzed.The performance of the heterojunction detector was ex-cellent and the manufacturing process was simple,providing a new avenue for the development of Ga2O3 ultrasensi-tive solar-blind UV photodetectors.
Ga2O3metal-organic chemical vapor deposition(MOCVD)heterojunctionsolar-blind UV photodetec-tors