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 a morphous hydrogenated Si a-Si:H[Er] was studied for the first time. The fil ms were obtained either by cosputtering of Si and Er targets with the use o f the technology of dc silane decomposition in a magnetic field (MASD) or b y 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 t emperature, the a-Si:H[Er] films obtained by the MASD method feature the ch aracteristic times of Er photoluminescence decay equal to 10-15 mu s, 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 ob tained by radio-frequency decomposition of silane, the decay times of Er ph otoluminescence amount to 2 mu s. The difference in the photoluminescence d ecay times is related to dissimilarities in the local surroundings of Er at oms in the a-Si:H[Er] films obtained by different methods. (C) 2000 MAIK "N auka/Interperiodica".