Midwave-infrared negative luminescence properties of HgCdTe devices on silicon substrates

We have investigated the negative luminescence properties of a midwave-infrared (MWIR) HgCdTe photodiode (λ_co = 5.3 μm at 295 K) grown on a silicon substrate. The internal negative luminescence efficiencies measured using a self-referencing optical technique were 88% throughout the 3–5 μm spectral region and nearly independent of temperature in the 240–300 K range. This corresponds to an apparent temperature reduction of 53 K at room temperature and 35 K at 240 K. Efficiencies measured by an electrical modulation technique were consistent with the measured internal efficiencies and the measured reflectivity of the device. This is the highest efficiency and largest apparent reduction in temperature reported to date, and slightly higher than that measured earlier for photodiodes grown on CdZnTe despite a longer cut-off wavelength. These results provide further indication that the HgCdTe/Si photovoltaic device technology is capable of combining high quality with high yield.