Determination of recombination parameters in CdTe films on glass substrates by using open photoacoustic cell

In the present work we used open photoacoustic cell (OPC) technique to study the thermal properties and the surface recombination velocity of CdTe/glass samples. Experimental photoacoustic (PA) signal as a function of modulation frequency, in OPC configuration, was fitted to the theoretical expression for PA signal amplitude, in appropriate frequency range, to obtain the sample thermal diffusivities; after this it was obtained the surface recombination velocity by fitting the experimental PA signal to the theoretical PA signal phase, which takes into account the heat sources resulting from the absorption light in semiconductors, The samples under study were polycrystalline CdTe film deposited on glass slides. CdTe layers were deposited by gradient recrystallization and growth (GREG) technique. By varying the deposition times three different CdTe films thicknesses were obtained. A small increment in the thermal diffusivity is observed as the thickness of the CdTe layer increase while the recombination surface velocity have a clear increment.