Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Investigation of high-efficiency monolithic multibandgap solar cells. Final report, 15 Nov 90-15 Nov 91

Technical Report ·
OSTI ID:6967371
This program involved investigations of AlGaAs/GaAs multijunction solar cells. Most of the low level effort was devoted to studies of the electronic properties of AlGaAs films. Finite diffusion lengths could only be obtained for Al(x)Ga(1-x)As films with the aluminum concentration in the range from 0 to 0.1. Photoresponse of Al/AlGaAs Schottky barriers were analyzed to measure minority carrier diffusion length (L). Values of L for p-type AlGaAs with x=0 were typically in the range of 0 to 0.5 micron. It is clear that much more effort must be made to reduce oxygen and water impurity levels in the WSU barrel-type reactor before improved AlGaA Schottky barriers is explained as being due to improper mixing of Al and Ga precursors. Results are discussed for films grown with improved mixing which do not exhibit the apparent bandgap shift. Estimated performance for a two-cell, AlGaAs/GaAs structure are given based on characteristics of Al(.37)Ga(.63)As cells fabricated from wafers obtained from Varian, and GaAs cells fabricated for epi wafers grown with the WSU reactor.
Research Organization:
Washington Univ., Seattle, WA (United States)
OSTI ID:
6967371
Report Number(s):
AD-A-254326/2/XAB; CNN: AFOSR-91-0095
Country of Publication:
United States
Language:
English