Nitride-based UV Schottky barrier photodetectors (PDs) with Ir/Pt after annealing in O2 at 600 °C were fabricated successfully. With -5 V applied bias, the reverse leakage current of the annealed PD was 3.65 × 10-12 A. It was found that we could achieve the larger Schottky barrier height, the smaller dark current and the larger photocurrent to dark current contrast ratio by annealing Ir/Pt. After annealing, the Schottky barrier height increased from 0.91 eV to 1.03 eV and the ideality factor decreased from 1.58 to 1.16. Such a result indicated that the dominant current transport mechanism may be thermionic emission and the Schottky contact is near-ideal after annealing. These results could be attributed to the formation of IrO x phase. It was also found that responsivity and the UV-to-visible rejection ratio were 0.19 A/W and 1.05 × 103 after annealing with -6 V applied bias.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry