451 ture. GaInP2 with good phototuminescence characteristics has been grown by m e t a l organic chemical vapor deposition using trimethylindium, trimethylgallium and phosphine, Shallow homojunctions in GaInP2, heterotunnel junctions between GaInP2 and GaAs, and full GaInP2/GaAs cascade devices have also been fabricated. Recent progress and results are presented and discussed. This work is supported by the Solar Energy Research Institute under Department of Energy Contract DE-AC02-83CH10093.
Amorphous ahoy tandem junction solar cells* VIKRAM DALAL and JAMES BOOKER
Spire Corporation, Bedford, MA 01730 (U.S.A.) In this paper we describe the design, preparation and properties of amorphous silicon alloy tandem junction solar cells. We address the following factors: tunnel junctions; current matching; quantum efficiency; fill factor; spectral characteristics; measurement techniques; stability; material properties; device design. It will be shown that an appropriate choice of material properties and device design can allow the preparation of reasonably efficient tandem junction cells. This work is supported in part by the Solar Energy Research Institute under Subcontract ZB-4-3055-1.
CdTe/CuInSe2 multijunction solar cells* J. D. MEAKIN, R. W. BIRKMIRE and J. E. PHILLIPS
Institu te of Energy Conversion, University of Delaware, Newark, DE 19716 (U.S.A.) The II VI and related chalcopyrite compounds provide many candidate materials for large-area thin film polycrystalline solar cells. CdTe and CuInSe2 single-junction heterojunction cells exceeding 10% efficiency have been demonstrated using CdS or (CdZn)S as the window layer. Although these absorbers do not have ideal band gaps for a twojunction cell their demonstrated single-junction performances indicate that a tandem cell of over 15% efficiency is achievable. Substantial scope for further improvement is provided by band gap control using the alloy systems based on these compounds, such as (CdZn)Te and Cu(InGa)Se2. The present status of polycrystalline tandem junction development will be described and the major developments needed to realize the full potential of these structures will be identified. This work is supported by the Solar Energy Research Institute under Subcontract 4-04025-1.
*Abstract of a paper presented at the 7th Photovoltaic Advanced Research and Development Project Review Meeting, Denver, CO, U.S.A., May 13, 1986.