Metal Organic Chemical Vapor Deposition Growth and Characterization of AlInN-Based Schottky Ultraviolet Photodiodes on AlN Template

AlInN-based Schottky ultraviolet photodiodes on AlN template are demonstrated. AlInN/GaN structures are grown using metal organic chemical vapor deposition. AlInN layer on AlN template exhibits high crystal quality and good surface morphology as it was confirmed respectively through X-ray diffraction (XRD) and atomic force microscope (AFM). The fabricated Schottky photodiodes on AlN template have the leakage current of 16 nA at a reverse voltage of 5 V and the cut-off wavelength around 260 nm. A zero-bias peak responsivity of 33 mA/W is achieved at 230 nm, corresponding to the quantum efficiency of 17%. This efficiency for AlInN-based photodiode on AlN template is superior to the photodiode grown on sapphire with low temperature buffer layer (LT-BL). It is possible to realize a high-performance AlInN-based Schottky photodiode by using AlN template as a substrate.