基于p-n结中反常光电转换现象的新型带间跃迁量子阱红外探测器

Anomalous light-to-electricity conversion of low dimensional semiconductor in p-n junction and interband transition quantum well infrared detector

实验发现p-n结中局域载流子具有极高抽取效率,同时伴随着吸收系数的大幅度增加.本文报道上述现象的发现和验证过程,以及基于此现象的新型带间跃迁量子阱红外探测器(interband transition quantum well infrared detector,IQWIP)原型器件的性能.采用共振激发光致发光光谱技术,在InGaN量子阱、InGaAs量子阱、InAs量子点等多个材料体系中均观察到了在p-n结电场作用下的载流子高效逃逸现象,抽取效率分别为95%,87.5%,88%.利用含有InGaAs/GaAs多量子阱的PIN二极管,实验尝试了制备新型的IQWIP原型器件.在无表面减反射膜的实验条件下,利用仅100 nm的有效吸收厚度,实现了31%的外量子效率.基于这个数值推算得到量子阱的光吸收系数达到3.7×10~4cm^(-1),该数值高于传统透射实验测量体材料和量子阱结果.此外,还利用InAsSb/GaSb量子阱材料体系进行了2μm以上波长红外探测的探索.利用上述现象,有望在提高现有器件性能的同时开发出新颖的光-电转换器件.

Recently, high localized carrier extraction efficiency and enhanced absorption coefficient were observed in low- dimensional semiconductor within a p-n junction. In this work, we report the discovery and verification of the phe- nomenon, and the performance of the first photon detector based on the interband transition of strained InGaAs/GaAs quantum wells （QWs）. By introducing the resonant excitation photoluminescence, the same phenomena are observed in several different material systems. More than 95% of the photoexcited carriers escape from InGaN/GaN QWs, and 87.3% in InGaAs/GaAs QWs and 88% in InAs/GaAs quantum dots are observed. The external quantum efficiency of the device is measured to be 31% by using an absorption layer with only 100 nm effective thickness in the case without an anti-reflection layer. Using such a high value of quantum efficiency, an absorption coefficient of 3.7 × 104 cm-1 is calculated, which is obviously larger than previously reported values. The results here demonstrate the possibility of fabricating high-performance and low-cost infrared photon detectors.