FOURIER-TRANSFORM INFRARED PHOTOLUMINESCENCE OF HG1-XCDXTE

A novel double modulation technique for Fourier transform infrared luminescence spectroscopy is described which facilitates sensitive measurements in the long wavelength ( ≈10 μm) region normally dominated by thermal background radiation. This technique has been used to study the luminescence of Hg1-xCdxTe (MCT) bulk crystals with x = 0.22 and x = 0.34 grown by the travelling heater method. Luminescence of bulk MCT in the 10 μm range is reported for the first time (x = 0.22). The dependence of the luminescence spectra on temperature and excitation power has been studied. For the x = 0.22 sample, substantial luminescence line broadening is observed with increasing excitation power. This behaviour is attributed to band filling effects in the conduction band. From the above data, the lifetime of the photogenerated carriers of 0.4 μs is deduced. The temperature dependence of the luminescence indicates contributions from transitions with slightly relaxed wavevector conservation. Corresponding data for a MCT sample with x = 0.34 are presented using excitation powers down to 35 μW (power densities 0.2 Wcm-2). © 1989.