Effects of low argon dilution ratio on the nanocrystallization and properties of a-Si:H thin films.
The structure and properties of thin films obtained by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) through decomposition of silane mixed with argon have been studied by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, ultraviolet and visible (UV-vis) spectroscopy and transmission electron microscope (TEM), respectively. The dilution ratio increases from 6 to 24, and other deposition parameters are fixed. It is observed that argon as dilution gas in the deposition process benefits the development of nano grains and the growth of thin films. The crystalline volume fraction, grain size and hydrogen content of the films increase with the increase argon dilution ratio. The dark conductivity of the thin films is measured, and the results show that the increase of crystalline volume fraction improves the electrical property of the films. The optical gap of the films is calculated from details of the spectra measured by UV-vis. The decrease of optical gap of the films with the increase of argon dilution ratio has been observed.
UESTC, School of Optoelectronic Information, Chengdu 610054, China.
Zhi
Z
Li
Wei
W
Li
Haihong
H
Cai
Yuguang
Y
Gong
Yadong
Y
Jiang