Study on material characterization and device performance of non-uniform GaAs/AlGaAs quantum well infrared detectors
In this paper,the GaAs/AlGaAs non-uniform quantum well infrared detector material was successfully grown by molecular beam epitaxy(MBE),and the microstructure was characterized in detail.The performance differ-ence between the non-uniform quantum well structure and the conventional quantum well infrared detector is analyzed and compared,and the performance change of the non-uniform quantum well infrared detector under different well widths is comparatively studied.The microstructure of non-uniform quantum well infrared detector materials was ana-lyzed by high resolution transmission electron microscopy(HRTEM)combined with energy dispersive spectroscopy(EDS),and the non-uniform well doping was characterized by secondary ion mass spectrometry(SIMS).The results show that the crystal quality of the non-uniform quantum well epitaxial material is very good,and the non-uniform quan-tum well structure and doping concentration are also in good agreement with the design values.The results show that for non-uniform quantum well infrared detectors,the electric field distribution of the quantum well can be modulated by changing the doping concentration and barrier width of each well,and the dark current significantly decreases(by about an order of magnitude),compared with traditional uniform quantum well infrared detectors.Moreover,under different well widths,the transition modes of non-uniform quantum wells can change,and the devices with bound state to quasi-bound state transition modes(B-QB)have better blackbody response and lower dark current.
quantum well infrared photodetectorhigh resolution transmission electron microscopesecondary ion mass spectroscopydark current