Study Of Photoelectric Properties Of A-Si:H Deposited By MW-ECR CVD

As a new-type functional material, developed in recent 20 years,hydrogenated amorphous silicon thin films (a-Si:H) is increasinglyplaying an important role in the high-technology field of new energyresources and information display. However, the light-induceddegradation (Staebler Wronski Effect) of a-Si:H thin films upon thelight-soaking seriously restricts its further development andapplication. Although intensive research has been carried out, since itsdiscovery, to illustrate the mechanism of this effect, unanimousagreement has not been achieved until now. It has been gradually realizedthat the metastable properties of a-Si:H thin films is closely relatedwith the amorphous network and hydrogen atoms within the films. The main content of this thesis is to test and study the photoelectricproperties of a-Si:H deposited by microwave electron cyclotron resonancechemical vapor deposition (MW-ECR CVD) system. Including three partsmainly: Firstly, a simple introduction of experiment system; Secondly,the adjustment of technology parameter and betterment of MW-ECR CVDfurther more by hot wire assisted in order to deposit high-quality a-Si:Hthin films by analysis the effect of different deposition conditions ontheirs photoelectric properties; Thirdly, the study of microstructure andanalysis of the microcosmic indication of a-Si:H thin films of differentphotoelectric properties by FT-infrared spectra and Micro-Raman scatterspectra. Since there are many factors affect the photoelectric properties ofa-Si:H thin films, we have studied the effect on the photosensitivity andstability of the ratio of hydrogen dilution, the temperature ofsubstrate, the temperature of hot wire and so on. The photoelectric properties of a-Si:H thin films is closely related II摘 要with its composition and microstructure. The entrance of hydrogen atomsmake a fundamental change to the photoelectric properties of amorphoussilicon. Plentiful experiment results show that the light-induceddegradation of a-Si:H thin films perfectly corresponds to the content ofSiH2 in the films. The higher content of SiH2 , the more remarkabledegradation. And the improvement of photosensitivity is ascribed to thedecrease of (SiH2)n, Si-Si and hydrogen content.