https://doi.org/10.15407/iopt.2024.59.124

Optoelectron. Semicond. Tech. 59, 124-132 (2024)

S.M. Levytskyi, Z. Cao*, A.V. Stronski


LASER-INDUCED NANOSECOND PULSE PROCESSES OF MASS TRANSFER AND FORMATION OF INVERSION AND VARIZON LAYERS IN SOLID SOLUTIONS BASED ON CADMIUM TELLURIDE


In this work, such non-linear simultaneously occurring physical processes as thermo- and baro-diffusion, concentration diffusion, the process of emergence and propagation of a shock wave during nanosecond laser irradiation of metal film (In)/CdTe structures were studied. The dominant mechanism of mass transfer is established. Spectra of low-temperature photoluminescence of CdTe after irradiation of its surface and In/p-CdTe structure were obtained. It was established that after the laser-induced introduction of indium, the intensity of photoluminescence increases in the short-wavelength region - in the region of free excitons. At the same time, it was established that an n-type inversion layer is formed. It was found that the maximum of the indium distribution at 6 nm corresponds to the minimum of the cadmium distribution, which indicates the diffusion of internodal In atoms through Cd vacancies. 

It is shown that the mechanisms of concentration diffusion of indium in CdTe and entrainment of In atoms by the laser-induced shock wave front during its occurrence and propagation are not the dominant and determining mechanisms of indium mass transfer in the In/CdTe structure with an In film thickness of 30-400 nm under nanosecond laser irradiation.The calculated average drift rate of diffusion of In atoms in CdTe, the obtained value of the rate of laser-induced mass transfer of In in CdTe is commensurate with the rate of diffusion of metal atoms in some semiconductors under pulsed laser irradiation.

The calculations made in the framework of this work can be applied to most structures of a metal-semiconductor film for the analysis of mass transfer (diffusion processes) in different parts of the volume of the structure during pulsed laser irradiation in the process of manufacturing various functional semiconductor structures.


Keywords: CdTe, CdZnTe, laser irradiation, mass transfer, doping, nanosecond laser irradiation, shock wave, diffusion, In/CdTe.