An Anomalous Gain Mechanism in GaN Schottky Barrier Ultraviolet Photodetectors

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2009,（5）
• 页码范围: 251-254
• 页数: 4页
• 语种: 英文

摘要

The gain mechanism in GaN Sehottky barrier ultraviolet photodetectors is investigated by focused light beam.When the incident light illuminates the central region of the Schottky contact electrode, the responsivity changes very little with the increase of reverse bias voltage. However, when the incident light illuminates the edge region of the electrode, the responsivity increases remarkably with the increase of reverse bias voltage, and the corresponding quantum efficiency could be even higher than 100%. It is proposed that the surface states near the edge of the electrode may lead to a reduction of effective Schottky barrier height and an enhancement of electron injection, resulting in the anomalous gain.