Photocurrent Property of GaN on the Si Photodetector with a Nearly Polycrystalline α-Al2O3 Buffer Layer

• 来源期刊: 中国物理快报（英文版）
• 学科: 物理学
• 年，卷（期）: 2002,（10）
• 页码范围: 1553-1555
• 页数: 3页
• 分类号: O4
• 语种: 英文

摘要

Using nearly polycrystalline α-Al2O3 as the buffer layer, GaN epilayers were grown on Si(111) substrates by low-pressure metal-oragnic chemical vapour deposition. The nearly polycrystalline α-Al2O3 was formed by anodicporous alumina annealed at high temperature. Prototype photoconductive detectors were fabricated with thesematerials. The spectral response of these detectors exhibits a relatively sharp cut-off near the wavelength of360nm and a peak at 340nm with a shoulder near 360nm. Under 5 V bias, the responsivities at 340nm and360nm were measured to be 3.3 A/W and 2.4A/W, respectively. The relationship between the responsivity andthe bias voltage shows that the responsivity is saturated when the bias voltage reaches 5 V.