Negative luminescence with 93% efficiency from midwave infrared HgCdTe diode arrays

We have investigated the negative luminescence (NL) properties of an array of HgCdTe photodiodes (λco=4.6 μm at 295 K) as a function of temperature and wavelength. The internal NL efficiency of ≈93% at λ=4.0 μm is nearly independent of temperature in the 240–300 K range, and at 296 K corresponds to an apparent temperature reduction of 54 K. This is obtained at a reverse-bias saturation current density of only 0.13 A/cm2 at 296 K, which is attributable in part to an array geometry that reduces the influence of macroscopic defects. These observed NL performance characteristics are compatible with most of the requirements for applications such as cold shielding.