Properties of InSb Photodiodes Fabricated by Liquid Phase Epitaxy

High detectivity InSb photodiodes have been developed by using the liquid phase epitaxy technique. They have n on p structure. Infrared radiation absorption in the Te doped n layer is quite small, due to the Burstein-Moss effect. The quantum efficiency of the photodiode is limited only by diffusion length Ln of minority carriers in the p region. Values obtained were from 0.2 to 0.3. The zero bias resistance of 2 mm diodes was from 100 to 200 kΩ. Specific detectivity Dλ*(λ=5 µm, frequency 1 kHz) was from 5×1010 to 1×1011 cmHz1/2/W.