Low Temperature Back-Surface-Field (BSF) Technology for Crystalline Silicon (c-Si) Thin Film Solar Cells Based on Heterojunctions between Boron-Doped P-Type Hydrogenated Amorphous Silicon and c-Si
We propose a low temperature back-surface field (BSF) technology for crystalline silicon (c-Si) thin film solar cells. The BSF structure has a heterojunction between a p-type c-Si substrate and a boron (B)-doped p-type hydrogenated amorphous silicon (a-Si:H) layer deposited on the back surface of the c-Si substrate at 200degC. The back-surface recombination velocity, Sb, of minority carriers can be reduced to less than 1000 cm/s in this structure, while the value of S b is 106 cm/s when a B-doped p-type layer is epitaxially grown on the c-Si substrate. We have clarified, from internal photoemission (IPE) and attenuated-total-reflection Fourier transform infrared (ATR-FTIR) spectroscopy measurements, that possible reasons for the observed low value of Sb are (1) the band lineup of the heterojunction (HJ) between B-doped p-type a-Si:H and c-Si and (2) the hydrogen passivation of defects in B-doped a-Si:H
Electronic and optical properties of boron doped hydrogenated amorphous silicon thin films
Abstract The electronic and optical properties of p-type a-Si:H films prepared by the rf glow discharge decomposition of a mixture of silane and diborane gases have been studied. The films have been prepared under different conditions which include variation of volume ration of B 2 H 6 and SiH 4 and rf power. The properties of compensated a-Si:H films prepared with very small boron doping have also been studied. The effects of mixing Ar with SiH 4 + B 2 H 6 mixture have been investigated. The properties actually studied include (1) dark conductivity, (2) steady state photoconductivity, (3) spectral response, (4) optical absorption and band gap. Attempts have been made to analyse the data to yield information about the transport mechanism, and the existence of hole and electron traps.
The politics of affect and emotion in contemporary Latin American cinema : Argentina, Brazil, Cuba, and Mexico
Between Neo-realist Sentimentality and Modernist Shock: New Latin American Cinema and Beyond Thrilling Histories: Questions of Genre and History Affecting Legacies: Contemporary Structures of Feeling Alien/Nation: Contemporary Youth in Film Emotional Investments: Global Networks and Transnational Affective Communities