H. Kato et al., Thermally induced photoluminescence quenching centre in hydrogenated amorphous silicon oxynitride, J PHYS-COND, 13(30), 2001, pp. 6541-6549
The effect of thermal annealing on the photoluminescence around 2.2-2.9 eV
in hydrogenated amorphous silicon oxynitride films was investigated. The lu
minescence intensity increases monotonically with an increase in the anneal
ing temperature for the samples with lower nitrogen contents (N/O = 0.06, 0
.10 and 0.12). It shows a similar increase up to 500 degreesC, while it dec
reases abruptly above 500 degreesC for the samples with higher nitrogen con
tents (N/O = 0.14 and 0.18). The density of silicon dangling bonds depends
on the annealing temperature in a manner opposite to that of the luminescen
ce intensity in all the temperature region. Based on this correlation, it i
s thought that the silicon dangling bonds act as the quenching Centre. Infr
ared absorption spectroscopy indicated that the precursor of silicon dangli
ng bonds was the Si-H bond. Hydrogen was released at temperatures above 500
degreesC from Si-H bonds, resulting in a large number of silicon dangling
bonds that quench the luminescence.