MIS and SIS solar cells on polycrystalline silicon

Abstract

Metal-Insulator-Semiconductor (MIS) and Semiconductor-Insulator-Semiconductor (SIS) structured solar cells have been considered a viable alternative to thermally diffused p-n junctions for use on polycrystalline thin-film silicon substrates. Early work indicated that thermal diffusion of a j~mction in polycrystalline silicon substrates could impose severe problems. Experimental investigations have shown that a p-n junction in polycrystalline silicon can have well behaved characteristics. The major efficiency loss mechanism, introduced by the presence of grain boundries, apparently does not come from the lower value of shunt resistance but from the additional recombination loss along the grain boundaries. This paper's purpose is to review the status of MIS and SIS solar cell technologies and assess the potential of these structures to meet low cost goals. Three major types of MIS/SIS solar cells are discussed in terms of structure, materials used in the fabrication, and the current collection under illumination~ The types of solar cells discussed include the thin metal MIS structure, the conducting oxide SIS structure, and the MIS inversion layer device. The specific advantages of a MIS/SIS solar cell are investigated by the use of theoretical calculations. The spectral response, short circuit current, open circuit voltage, fill factor, and cell efficiency have been calculated for the MIS/SIS case, the advanced diffused, and standard diffused solar cells. Several specific problem areas exist with these devices. The possible loss mechanisms in the MIS/SIS device are detailed, the cell stability and degradation mechanisms are identified, and the fabrication techniques amenable to large scale use are discussed. A major conclusion of the paper is that the MIS/SIS solar cells have no apparent advantage over diffused p-n junctions.

Advancement of Schottky Barrier Solar Cells: A Review

“…Check et al analyzed the possibility of MIS/SIS cells on polycrystalline base material and concluded that MIS/SIS based polycrystalline cells have better blue response than the diffused cells. In diffusion process high temperature forms dead layer in polycrystalline cells but due to lower process temperature in fabrication of MIS/SIS cells no dead layer is formed and incase of diffused cells, four times higher grain boundary is required than the SIS/MIS cells to obtain same cell efficiency (Cheek, 1979).…”

Carrier‐selective contacts using metal compounds for crystalline silicon solar cells

“…The concept of using metal‐compound thin films, particularly metal oxides, as contact interlayers in c ‐Si cells is not new. Early work in the 1970s on c ‐Si semiconductor–insulator–semiconductor (SIS) solar cells identified a number of promising candidates, 3 including molybdenum trioxide MoO 3, 3,4 a popular choice today as a contacting layer to provide hole selectivity. Performance at that time was limited to efficiencies around 10%, which was still thought of as promising compared to state‐of‐the‐art 5 .…”

MIS and P/N Junction Solar Cells on Thin-Film Polycrystalline Silicon

“…The MIS and SIS solar cells should ha't41 an enhanced short wavelength response because of the absence of a "dead layer" usually present in p/n junctions (1). Thus, the MIS-type cells should perfonn better than p/n junctions on Slllall grain polycrystalline silicon where the diffusion length is expected to be short.…”