LAUSR

A method to extend the operating wavelength of the interband transition quantum well photodetector from extended short-wavelength IR to middle-wavelength infrared has been introduced. In the modified InAsSb quantum well, GaSb is replaced with AlSb/AlGaSb, the valence band of barrier material is lowered, the first restricted energy level (E1) is higher than the valence band of barrier material, the energy band structure forms type-II structure. The photocurrent spectral manifested that the fabricated photodetector exhibited a response range from 1.9 μm to 3.2 μm with two peaks at 2.18 μm and 3.03 μm at 78 K.