Plasma deposition of thin film silicon: kinetics monitored by optical emission spectroscopy

The optical emission spectroscopy technique is used to characterise the temporal behaviour of a pure silane plasma in the first 90 s after ignition of a static closed-chamber very high frequency glow discharge. Special interest is drawn to the formation of microcrystalline silicon (μc-Si:H) in absence of any hydrogen feedstock gas dilution. The kinetics of the emission lines of SiH* and H_α is reported. The deposited films are characterised by photothermal deflection spectroscopy, Fourier transform infra red (FT-IR) absorption and show typical microcrystalline fingerprints; for the first time, such material is used as absorber layer in n–i–p type solar cell devices.