| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 97 === In this thesis, the p-type amorphous silicon carbide (a-SiC) and p-type hydrogenated microcrystalline silicon (μc-Si:H) films were deposited on glass by radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD) using trimethylboron (TMB) as the doping source. For optimization of the window layer, the dependence of electrical and optical properties were investigated.
In the first part, we deposited p-type a-SiC with methane and silane. The dark conductivity and optical gap of the film deposited at [CH4]/[SiH4]=2 were 4.9 10-7 S/cm and 2 eV, respectively. The result showed that the films were more transparent than amorphous silicon.
In the second part, the crystalline volume fraction of μc-Si:H were enhanced with increasing hydrogen dilution. The crystalline volume fraction of 52% and dark conductivity of 1.31×10-1 S/cm can be achieved under the following condition: [H2]/[SiH4]=100 and Ts=220oC. This result showed that the film with thickness of 85 nm possessed a good electrical property. However, it’s too thick for the window layer in the thin film solar cell. Finally, a thinner film with thickness of 35 nm which we deposited had a high dark conductivity around 10-2 S/cm after the sample annealed under Ar atmosphere at 200oC for 1 hr, and it was suitable for thin film solar cell.
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