Quarterly progress report on the evaluation of critical materials for photovoltaic cells

Abstract

PNL-3234 UC-63 FI GURES TABLES some of the general cell types and, in some cases, several candidate materials for a particular device function are examined. Examples are the homojunction, heterojunction and r~IS structures possible for polycrystalline Si cells and the use of either ITO or Sn0 2 as the window layer of the heterojunction structure. Also selected for study by the workshop participants were the processes listed below for fabrication of materials used in the selected cell types. These processes are examined in this study for materials usage efficiency:

Evaluation of critical materials in five additional advance design photovoltaic cells

“…State-ofthe-art InP/CdS solar cells employ layer thicknesses designated as "most likely". Planar reactive deposition process is discussed in a later section while all other processes have been discussed elsewhere (R. L. Watts et al, 1979). A 10% cell conversion efficiency was assumed for the baseline InP/CdS ce 11 .…”

“…The close spaced vapor transport deposition process and the plasma polymerization process are discussed in a later section. All other processes have been discussed elsewhere (R. L. Watts et al, 1979).…”

“…A 10% cell conversion efficiency was assumed for the baseline cell. Deposition processes have been discussed elsewhere (R. L. Watts et al 1979).…”

“…Process efficiency numbers assume an 80% packing density of cells on the substrate. All other deposition processes have already been discussed (R. L. Watts et al 1979) Screen Printing, Brush Technique, Painting Screen printing, the brush technique and painting are similar from a process efficiency point of view. Process efficiencies are near 80% since all material (material suspended in organic binder and flux) not deposited on the substrate is returned to the storage vessel and reused.…”

“…Chapter 2 describes the CMAP methodology used to identify critical materials. Chapter 3 of this report provides detailed characterizations of the advanced photovoltaic cell designs under investigation, descriptions of additional cell production processes (Watts et al 1979), and the results of this investigation.…”