The influence of local surroundings of Er atoms on the kinetics of decay of Er photoluminescence in amorphous hydrogenated silicon

Kinetics of the decay of photoluminescence of Er impurity in the films of amorphous hydrogenated Si a-Si:H〈Er〉 was studied for the first time. The films were obtained either by cosputtering of Si and Er targets with the use of the technology of dc silane decomposition in a magnetic field (MASD) or by radio-frequency decomposition of silane. In the second case, an Er(TMHD)₃ polymer powder was used as the source of Er. It is shown that, at room temperature, the a-Si:H〈Er〉 films obtained by the MASD method feature the characteristic times of Er photoluminescence decay equal to 10–15 µs, which is 20 times smaller than in the case of Er-doped crystalline Si (c-Si〈Er, O〉) as measured at liquid-nitrogen temperature. For the a-Si:H〈Er〉 films obtained by radio-frequency decomposition of silane, the decay times of Er photoluminescence amount to 2 µs. The difference in the photoluminescence decay times is related to dissimilarities in the local surroundings of Er atoms in the a-Si:H〈Er〉 films obtained by different methods.