NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
High-efficiency, deep-junction, epitaxial InP solar cells on (100) and (111)B InP substratesWe report on the development and performance of deep-junction (approximately 0.25 micron), graded-emitter-doped, n(sup +)-p InP solar cells grown by metallorganic chemical vapor deposition (MOCVD). A novel, diffusion-transport process for obtaining lightly-doped p-type base regions of the solar cell is described. The I-V data and external quantum-efficiency response of these cells are presented. The best active-area AMO efficiency for these deep-junction cells on (100)-oriented InP substrates is 16.8 percent, with a J(sub SC) of 31.8 mA/sq cm, a V(sub OC) of 0.843 V, and a fill-factor of 0.85. By comparison, the best cell efficiency on the (111)B-oriented InP substrates was 15.0 percent. These efficiency values for deep-junction cells are encouraging and compare favorably with performance of thin-emitter (0.03 micron) epitaxial cells as well as that of deep-emitter diffused cells. The cell performance and breakdown voltage characteristics of a batch of 20 cells on each of the orientations are presented, indicating the superior breakdown voltage properties and other characteristics of InP cells on the (111)B orientation. Spectral response, dark I-V data, and photoluminescence (PL) measurements on the InP cells are presented with an analysis on the variation in J(sub SC) and V(sub OC) of the cells. It is observed, under open-circuit conditions, that lower-V(sub OC) cells exhibit higher band-edge PL intensity for both the (100) and (111)B orientations. This anomalous behavior suggests that radiative recombination in the heavily-doped n(sup +)-InP emitter may be detrimental to achieving higher V(sub OC) in n(sup +)-p InP solar cells.
Document ID
19950014091
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Venkatasubramanian, R.
(Research Triangle Inst. Research Triangle Park, NC, United States)
Timmons, M. L.
(Research Triangle Inst. Research Triangle Park, NC, United States)
Hutchby, J. A.
(Research Triangle Inst. Research Triangle Park, NC, United States)
Walters, Robert J.
(Naval Research Lab. Washington, DC., United States)
Summers, Geoffrey P.
(Naval Research Lab. Washington, DC., United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1994
Publication Information
Publication: NASA. Lewis Research Center, Proceedings of the 13th Space Photovoltaic Research and Technology Conference (SPRAT 13)
Subject Category
Energy Production And Conversion
Accession Number
95N20507
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available