Long-Wavelength InAs/GaSb Superlattice Detectors With Low Dark Current Density Grown by MOCVD

High-performance long-wavelength InAs/GaSb superlattice infrared photodetectors grown by metal-organic chemical vapor deposition are reported. Diffusion-limited behavior has been achieved for three devices with different doping concentration of the absorbers. Increasing the absorber doping concentration from 5 x10(15) to 5x10(16) cm(-3) causes reduction of the dark current, decrease of the quantum efficiency, and blue-shift of the cutoff wavelength. The optimal device shows a 50% cutoff wavelength around 8.6 mu m, a dark-current density of only 6.8x 10(-6) A/cm(2) and a peak specific detectivity of 1.4x 10(12)cm.root Hz.W-1 at 77 K and a reverse bias of -0.1 V.

Automated summary

High-performance long-wavelength InAs/GaSb superlattice infrared photodetectors grown by metal-organic chemical vapor deposition exhibit diffusion-limited behavior, with the optimal device showing excellent performance at 77 K and a reverse bias of -0.1 V. Increasing absorber doping concentration from 5 x10(15) to 5x10(16) cm(-3) results in reduced dark current, decreased quantum efficiency, and a blue-shift of the cutoff wavelength.