Abstract: In this study, the variation of electron-lattice temperature in the nanosecond (ns) time regime nearly impossible with metals has been presented and it is clearly shown that non-equilibrium temperature in the nanosecond (ns) time regime of several hundreds of Kelvin temperature of transient hot electrons can be obtained using intrinsic and doped Indium-Antimonide thin film semi-conducting materials. It is shown that Ne(t) versus time profile for different thicknesses of different semi-conducting materials and the exponential growth rate as function of hot electron temperature and time, one can make an approximate estimate of the enhanced electron-concentration. The FWHM of the Te(t) versus time profile is usually around 1 to 4 nanosecond (ns) for film thicknesses of 100 A0 to 1.2 micron though, it increases with film thicknesses. The exponential growth rate varies on the average from 105 to 1010 as electron temperature increases. We noted that the value of the Ne(t)/No (which is the enhancement factor), using t of the order of FWHM is found to vary from 105 to 109. In other words, one can enhance the free electron concentrations in semiconductor conduction band for a time scale of 1 to 4 n sec, using our technique of electron pumping from valence band to conduction band with intense CO2 laser pulse. This is expected to significantly enhance the photo-emission by a suitably delayed probe laser with hv>Φ work function. The delay should be such that the probe laser is switched on after the cessation of the pump laser but within the FWHM period.