200 nm deep ultraviolet photodetectors based on AlN

High quality AlN epilayers were grown on sapphire substrates by metal organic vapor deposition and exploited as active deep ultraviolet (DUV) optoelectronic materials through the demonstration of AlN metal-semiconductor-metal (MSM) photodetectors. DUV photodetectors with peak responsivity at 200nm with a very sharp cutoff wavelength at 207nm have been attained. The AlN MSM photodetectors are shown to possess outstanding features that are direct attributes of the fundamental properties of AlN, including extremely low dark current, high breakdown voltage, and high DUV to visible rejection ratio and high responsivity. The results demonstrate the high promise of AlN as an active material for DUV device applications.