At present the investigations of nanosize clusters formation on crystal surface under laser irradiation is one of the prospective tasks in the semiconductor technology. The sizes and density of these structures ambiguously depend on physical nature of material, power density or irradiation dose, concentration of defects and other factors. Formation of nanostuctures depending on dose of laser irradiation was investigated in CdTe, as the last is promising material for development of advanced optoelectronic devices. It was shown that effect of accumulation plays the basic role in this process.
The question of intensity dependence of nanostructure formation on the surface of CdTe crystals is still open and actual.
The dependence of surface morphology of p-CdTe (111) crystals on power density of laser radiation was investigated by atom-force microscopy method. Photoconductivity (PC) spectra were studied at 300K and 77 K. Crystals were irradiated at T=300K by one pulse of the Q-switched ruby laser radiation with 2•10-8 s duration.
An averaging roughness of surface of inititial sample was about 0.075 nm. It was found, that irradiation of crystals results in formation of the nanostructures with lateral sizes about 19.3-46 nm and heights about 1-5.6 nm. Computer Fast Fourier transformation shows, that nanoclusters are periodic at specific power density of laser irradiation.
After irradiation of sample PC maximum due to band-zoned transition and several additional PC bands of low-intensity at high-energy portion of spectrum were observed in addition to impurity maximum. It was established the correlation between occurrence of additional PC bands and nanoclusters.
Experimental data analysis enabled to ascertain the intensity of laser radiation at which homogeneously distributed nanoclusters with minimum lateral sizes are formed on surface of CdTe crystals. Possible mechanisms of nanosize clusters formation are discussed

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