ABSTRACT
The photodetector based on AlAs/GaAs/AlAs heterostructures has a layer of self-assembled InAs quantum dots (QDs) and In0.15Ga0.85As quantum well (QW) imbedded in GaAs wide QW. A peculiar negative differential capacitance characteristic has been clearly observed near 100 K. A simple model is proposed and used to qualitatively describe and demonstrated that the InAs monolayer can effectively absorb photo-excited carriers. A high sensitivity micro-spectrometer based on 64 pixels QDs photodetector array has been designed and used for fluorescence detection.
Funding
This work was supported by National Scientific Research Plan (2011CB932903); Shandong Provincial Natural Science Foundation, China (Grant No. ZR2014FL026, ZR2015FL008).