Low-temperature photoluminescence measurements (down to 4.2K) were employed for the investigations of the defects and impurities in multi-crystalline Si (mc-Si) samples grown by block-casting. The optical properties of as-grown, irradiated by γ-rays, heat and H plasma treated samples were studied. It was found that C and O as the residual impurity atoms were responsible for the formation of the zero-phonon photoluminescence lines with 0.9355eV (T line) and 0.9652eV (I line) after heat treatments at 350 to 550C. The appearance of photoluminescence lines with the energies of 0.9697eV (A line) and 0.7894eV (C line) after a γ-irradiation could be attributed to the formation of C- and O-related centers, respectively. The comparison of the photoluminescence properties of the mc-Si samples with the mono-crystalline one was performed. It was shown that the main

peculiarities of the low-temperature PL spectra of mc-Si could be explained both by the influence of residual impurities and the residual strains in this material.

Impurities and Defects in Multicrystalline Silicon for Solar Cells - Low-Temperature Photoluminescence Investigations. A.V.Mudryi, A.I.Patuk, I.A.Shakin, A.G.Ulyashin, R.Job, W.R.Fahrner, A.Fedotov, A.Mazanik, N.Drozdov: Solar Energy Materials and Solar Cells, 2002, 72[1-4], 503-8