An improvement on short-wavelength photoresponse for a heterostructure HgCdTe two-color infrared detector

Abstract

Integrated HgCdTe two-color infrared detector arrays were fabricated and their spectral photoresponses measured. The top mid-wavelength infrared planar photodiode was processed by selective B + implantation and the bottom short-wavelength infrared P-N homojunction photodiode formed in situ during MBE growth by indium impurity doping. A preliminary 256 × 1 linear focal plane array of SWIR/MWIR HgCdTe was fabricated by mesa isolation, passivation and metallization. Detailed investigations on the inner mechanism of the short-wavelength narrow effect commonly associated with integrated HgCdTe two-color detectors have been carried out by combining experimental work with analytical analysis and numerical simulation. It is shown in this work that the short-wavelength narrow effect can be successfully alleviated by replacing the homostructure short-wavelength P-N junction with a heterostructure short-wavelength P-N junction which significantly improves the performance of the detector.

Numerical analysis of two-color HgCdTe infrared photovoltaic heterostructure detector

“…The simulation results with the minority carrier lifetime larger than 10ns are in agreement with the reported experimental results with similar LETI structures (Borniol et al 2003;Hu et al 2010). As shown in Fig.…”

Dependence of laser beam induced current on geometry of the junction for HgCdTe photodiodes

“…The carrier generation-recombination process is composed of Shockley-Read-Hall, auger, radiative and optical generationrecombination terms. Photo generation is simulated by raytracing [7,8]. The wavelength of the laser is 0.63µm and the spot diameter is 1.5µm.…”

Photoresponse of Long-Wavelength AlGaAs/GaAs Quantum Cascade Detectors

“…To prevent false-alarm and improve detection accuracy, two color FPAs were studied and fabricated [10][11][12]. Conventionally, two-color detection is achieved by two single-color detectors fabricated together.…”