Recent advances in negative luminescent technologies

ABSTRACT Negative luminescent (NL) devices, which to an IR observer can appear colder than they actually are, have a wide range of possible applications, including use as modulated IR sources in gas sensing systems and as thermal radiation shields in IR cameras. A further important use would be a calibration source for IR focal plane arrays where there are many potential advantages over conventional sources, including high speed operation (for multi-point correction) and lower power consumption. Such applications present considerable technological challenges as they require large area uniform devices (>1cm 2 ) with a large apparent temperature range. In this paper we report on recent progress in fabricating large area (1.5cm × 1.5cm) negative luminescence devices from Hg 1-x Cd x Te grown on silicon substrates using a segmented device architecture. 1. INTRODUCTION The phenomenon of negative luminescence (NL) has attracted considerable interest since its first demonstration in semiconductors in 1965 by Ivanov-Omski et al. [1]. NL occurs when electron and hole concentrations are reduced below their thermal equilibrium levels, suppressing radiative recombination. This breaks the equilibrium between the environment and the NL source which becomes a net absorber of thermal radiation. NL has been demonstrated in reverse biased infrared photodiodes in InSb/Al