Temperature Dependence of Thermoabsorption Spectrum of Lead Sulphide

The abasorption edge of lead sulphide has been measured over the temperature range from 300 K down to 18 K, using thermoabsorption measurements. Based upon the analysis of the thermoabsorption spectra the absorption edge enrgy E g , the temperature coefficient d E g /d T and the broadening factor \(\) have been obtained. Typical values of E g are as follows; E g =0.290±0.002 eV at 20 K, E g =0.308±0.003 eV at 85 K and E g =0.418±0.003 eV at 292 K, respectively. The absorption edge E g decreases linearly with decreasing temperature down to about 100 K and the temperature coefficient is 5.5×10 -4 eV/deg. The temperature coefficient of the broadening factor \(d/dT\) is about 0.3×10 -4 eV/deg., less than one tenth of d E g /d T . These values are discussed by comparison previously reported data.