An Al0.21 Ga0.79 NGaN p-i-n photodiode was designed with a heavily doped buried p+ -GaN layer associating an n++ - In0.3 Ga0.7 N layer to form a p+ n++ tunneling junction under the Al0.21 Ga0.79 p-i-n heterostructure. In contrast to conventional AlGaN-based p-i-n photodiodes, the inverted devices can have a low-resistivity n -type AlGaN top contact layer with a typical zero-bias peak responsivity of 0.1 AW at 315 nm corresponding to a quantum efficiency of around 39%. The zero-bias rejection ratio was about four orders of magnitude over the ultraviolet and visible regions of the spectrum. The typical dark current of the inverted devices was below 30 pA at a reverse bias of below 1.5 V. The leakage current at a 10 V reverse bias was as high as 5 nA caused by the presence of cracks in the Al0.21 Ga0.79 layers.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)