Acoustic response to the action of nanosecond laser pulses on an In/CdTe thin-film heterostructure

The photothermoacoustic method has been used for diagnostics of thermobarodynamic processes in the metal In(400 nm)/semiconductor (CdTe) thin-film system under nanosecond laser irradiation (7 ns, $\lambda$ = 532 nm) in natural conditions (in air) and in a liquid medium (water). From the analysis of the data obtained, the dependence of the pressure induced in the energy-release region on the irradiation energy density has been established and the melting threshold of In film has been determined. Under irradiation of In/CdTe in water, the pressure is higher than in air: 17 times higher at the melting threshold of In film and 30 times higher at twice the temperature. It has been found that the laser pulse treatment of In/CdTe/Au samples in water makes it possible to obtain diode structures with better parameters: smaller leak currents and a steeper current-voltage characteristic under the forward bias of the $p$–$n$ junction.