基于十八硫醇修饰的Al_(0.6)Ga_(0.4)N MSM光电探测器研究

Investigations of Al_(0.6)Ga_(0.4)N MSM Photodetectors Modified with Octadecanethiol

高Al组分的AlGaN材料的光谱响应范围在日盲紫外波段,但其表面较高的缺陷密度限制了其在日盲紫外探测领域的应用。为此,研究了表面修饰对AlGaN基日盲紫外光电探测器件的性能影响。采用化学自组装方法,将十八硫醇有机分子化学吸附在高Al组分的Al_(0.6)Ga_(0.4)N表面,制备出表面修饰的AlGaN基金属-半导体-金属型日盲紫外光电探测器件。与未经修饰的光电探测器对比验证了这种修饰过程能有效减少AlGaN材料的表面状态引起的不利影响,降低器件的漏电流,并显著提高器件响应度,从而实现具有高响应度的AlGaN基金属-半导体-金属型日盲紫外光电探测器制备。

The spectral response range of the high Al-content AlGaN material is in the solar-blind ultraviolet band,but the higher trap density on its surface limits its application on the fields of solar-blind ultraviolet detection.Therefore,the effect of surface modification on the performance of AlGaN-based solar-blind ultraviolet photodetectors was investigated.The chemical self-assembly method was adopted to chemically adsorb octadecanethiol organic molecules on the surface of the Al_(0.6)Ga_(0.4)N wafer to prepare a surface-modified AlGaN-based photodetectors.Compared with unmodified photodetector,this modification process could effectively reduce the adverse effects caused by the surface states of the AlGaN material,reduce the leakage dark current,and significantly improve the responsivity of the device,indicating the realization of AlGaN-based metal-semiconductor-metal solar-blind photodetectors with high performance.