论文部分内容阅读
对采用金属有机化学气相沉积方法生长的p-Al0.43Ga0.57N/i-Al0.43Ga0.57N/n-Al0.7Ga0.3N异质结构上制备的背照射日盲型AlGaN紫外光电探测器进行了光电性能和电容特性的研究。室温下探测器零偏压时的电流密度为0.44 nA/cm2,278 nm的峰值响应率为0.042 A/W。电容频率特性表明:器件电容随着频率的增大先迅速后缓慢地降低,但在频率高于100 kHz后又加速下降。通过器件低频下的电容计算可得,其耗尽层宽度为160 nm,低于设计的本征层厚度,说明器件的本征层没有完全耗尽。因此,未耗尽本征层的高电阻是引起100 kHz附近电容又快速下降的重要原因,由不同频率下1/C2-V曲线的变化关系及其斜率计算的杂质浓度等结果进一步证实了这一结论。
The back-illuminated solar-blind AlGaN ultraviolet photodetector prepared on the p-Al0.43Ga0.57N / i-Al0.43Ga0.57N / n-Al0.7Ga0.3N heterostructure grown by the metal organic chemical vapor deposition method The study of the photoelectric properties and capacitance characteristics. The current density at zero bias of the detector at room temperature is 0.44 nA / cm2 and the peak response rate at 278 nm is 0.042 A / W. Capacitor frequency characteristics indicate that the device capacitance decreases rapidly and then slowly with increasing frequency, but accelerates at frequencies above 100 kHz. Calculated by the capacitance of the device under low frequency, the depletion layer width of 160 nm, lower than the intrinsic layer thickness design, indicating that the intrinsic layer of the device is not completely depleted. Therefore, the reason why the high resistance of the intrinsic layer is not depleted is the cause of the rapid decrease of the capacitor in the vicinity of 100 kHz is further confirmed by the results of the variation of the 1 / C2-V curve at different frequencies and the calculated impurity concentration of the slope A conclusion.