μ-RAMAN SPECTRA ANALYSIS OF HYDROGENATED AMORPHOUS CARBON-SILICON ALLOYS A-SI{sub}XC{sub}(1-X)(N):H{sub}Y USED AS EMITTER WINDOW LAYERS IN HETERO-JUNCTION SOLAR CELL STRUCTURES

摘要

The fundamental properties of a-Si{sub}xC{sub}(1-x):H{sub}y thin films deposited using plasma enhanced chemical vacuum deposition (PECVD) with an additional methane source gas are investigated. The main goal is to suppress absorption in the emitter layer of a hetero-junction solar cell. The a-Si{sub}xC{sub}(1-x)(n):H{sub}y alloys are deposited on p-type silicon (100) substrates via PECVD using a gas mixture of silane (SiH{sub}4), phosphine (PH{sub}3), methane (CH{sub}4) and hydrogen (H{sub}2), respectively. Optical and electrical measurements have been used to characterize the a-Si{sub}xC{sub}(1-x):H{sub}y films regarding their properties of dark conductivity, σ, optical refractive index, n, and band gap, EG. μ-Raman spectra analysis derives information about the incorporation of carbon and hydrogen in the deposited thin films. Hetero-junction solar cells have been prepared with additional hydrogen and carbon and their IV-measurements are compared.