IEEE Electron Device Letters, cilt.43, sa.8, ss.1287-1290, 2022 (SCI-Expanded)
© 1980-2012 IEEE.We report diffraction-grating-free mid-wavelength infrared quantum well infrared photodetector pixels with small pitches (down to an area of 49 μm2) which exhibited remarkable peak conversion efficiency (70%) together with f/2 peak specific detectivity of ∼ 1.5×1011 cmHz1/2/W at 78 K. The sensors were fabricated with In0.85Ga0.15As quantum wells sandwiched between InP barriers. The pixels with 22% peak quantum efficiency exhibited background limited characteristics at 90 K with f/2 aperture and ∼ 6μm cut-off wavelength. All of the characteristics of the grating-free pixels scaled perfectly with the sensor area without suffering from the problems related with pitch reduction in the alternative technologies. The results demonstrate the potential of this sensor technology as a viable alternative to InSb, HgCdTe and Type-II superlattice sensor technologies for very small-pitch focal plane arrays.