高量子效率前照式GaN基p-i-n结构紫外探测器  

Characteristics of a Front-Illuminated Visible-Blind UV Photodetector Based on GaN p-i-n Photodiodes with High Quantum Efficiency

作　　者：游达[1] 汤英文[1] 赵德刚[2] 许金通[1] 徐运华[1] 龚海梅[1] 

机构地区：[1]中国科学院上海技术物理所传感技术国家重点实验室,上海200083 [2]中国科学院半导体研究所,北京100083

出　　处：《Journal of Semiconductors》2006年第5期896-899,共4页半导体学报（英文版）

摘　　要：研究了Al0.1-Ga0.9N／GaN异质结p-i-n结构可见盲紫外探测器的制备与性能,P区采用Al组分含量为0．1的AlGaN外延材料形成窗口层，使340-365nm波段的紫外光可以直接透过P区到达i区并被吸收，有效提高了这个波段的响应率与量子效率,并且研究了不同P区AlGaN外延层厚度对探测器性能的影响，制备了两种不同P区厚度（0．1μm和0．15μm）的器件，测试结果表明，P区的厚度对200-340nm波段光吸收的量子效率影响较大，而i区的晶体质量的提高可以有效提高340-365nm波段光吸收的量子效率,并且当P区AlGaN厚度为0．15μm时，器件的峰值响应率达到0．214A／W，在考虑表面反射时外量子效率高达85．6％，接近理论极限，并且在零偏压时暗电流密度为3．16nA／cm^2,表明器件具有非常高的信噪比。AlxGa1-x N/GaN hetero-epitaxial front-illuminated visible-blind UV photodetectors with very high external quantum efficiency are fabricated and characterized. Light between 340-365nm can be absorbed by i-layer by penetrating the p-AlGaN layer,so the quantum efficiency can be greatly enhanced. Then the effect of the p-AIGaN thickness on the characteristics of the detector is investigated, and two devices with different p-AIGaN thicknesses （0.1 μm, 0.15μm） are fabricated. The measurements show that the p-AlGaN thickness can only affect the responsivity of 200-340nm light, and the quality of the i-GaN layer can greatly affect the responsivity of 340-365nm light. The device with 0.15μm thick p-AIGaN has much higher quantum efficiency in the 340-365nm range, and the zero-bias peak responsivity is about 0. 214A/W at 365nm,corresponding to an external quantum efficiency of 85.6%. Moreover, this device exhibits a low dark current density of 3.16nA/ cm^2 at zero-bias,which indicates that the device has a very high SNR.

关 键 词：P-I-N AlGaN量子效率 响应光谱 紫外探测器 

分 类 号：TN23[电子电信—物理电子学]