The metastability of a-Si:H which deposited at different temperatures (250℃, 70℃, 90℃) and doping levels (500ppm, 2000ppm) was studied.
Samples deposited at 250℃ showed that dark conductivity decayed stretched exponentially with time, after rapid cooling. And lightly doped samples had longer relaxation time then highly doped samples. It was interpreted as a proof for hydrogen glass model by the fact that low doping level samples has small hydrogen diffusion coefficient, which had worked by Street et. al.
The relaxation behavior of the samples deposited at low temperature also showed stretched exponential form. By comparing relaxation time of 90℃ samples with 250℃ samples, the relaxation of deposition induced defect also can be interpreted by hydrogen glass model.
