GaN基肖特基结构紫外探测器

GaN Schottky Barrier Ultraviolet Detector

在蓝宝石 (0 0 0 1)衬底上采用低压金属有机物化学气相沉积 (MOCVD)方法生长GaN外延层结构 ,以此为材料制作了GaN基肖特基结构紫外探测器 .测量了该紫外探测器的暗电流曲线、C V特性曲线、光响应曲线和响应时间曲线 .该紫外探测器在 5V偏压时暗电流为 0 4 2nA ,在 10V偏压时暗电流为 38 5nA .在零偏压下 ,该紫外探测器在2 5 0nm～ 36 5nm的波长范围内有较高的响应度 ,峰值响应度在 36 3nm波长处达到 0 12A/W ,在 36 5nm波长左右有陡峭的截止边 ;当波长超过紫外探测器的截止波长 (36 5nm左右 ) ,探测器的响应度减小了三个数量级以上 .该紫外探测器的响应时间小于 2 μs.

A GaN Schottky barrier ultraviolet detector is fabricated using GaN films grown on sapphire substrates.Its dark current, C-V ,responsivity,and response time are measured at room temperature.The dark current of the detector is 0.42nA under 5V bias,and 38.5nA under 10V bias.A maximum responsivity of 0.12A/W is achieved under the illumination with λ =363nm light and 0V bias.It exhibits a typical sharp band-edge cutoff at the wavelength of 365nm,and a high responsivity at the wavelength of 250～365nm.The responsivity of the detector drops by nearly three orders of magnitude across the cutoff wavelength (365nm).Its response time is less than 2μs.