The electrical properties of Si-doped n+-In0.23Ga0.77N/GaN SPS structure were investigated and compared with conventional Mg-doped GaN contact layer. Temperature depend Hall measurement showed that such a SPS structure exhibits a high sheet electron concentration. It was found that we could reduce the 20 mA LED forward voltage from 3.78 V to 2.94 V and also reduce the series resistance of the LED from 41 Ω to 10 Ω by introducing such an n+-InGaN/GaN SPS top contact. It was also found that we could improve the LED lifetime by such a SPS structure.
- Hall measurement
- Tunneling contact