Effect of thermal annealing on optical and photoelectric properties of microcrystalline hydrogenated silicon films

The effect of thermal annealing in the temperature range T-a=300-600degreesC of films of microcrystalline hydrogenated silicon (muc-Si:H) lightly doped with boron on the spectral dependences of the absorption coefficient (alpha) at photon energies hnu=0.8-2.0 eV, dark conductivity (sigma(d)), and photoconductivity (Deltasigma(ph)) was studied at room temperature. With increasing annealing temperature, a nonmonotonic variation of alpha (at hnu<1.2 eV), sigma(d), and Deltasigma(ph) was observed. The data obtained are attributed to a change in the concentration of electrically active impurities and formation of defects, caused by hydrogen effusion and bond restructuring at high annealing temperatures. (C) 2003 MAIK "Nauka/Interperiodica".