Gettered GaP Substrates for Improved Multijunction Solar Cell Devices

Authors

Kyle H. Montgomery, Charles R. Allen, Isaac H. Wildeson, Jong-Hyeok Jeon, Anant K. Ramdas, Jerry M. Woodall

Publication

Journal of Electronic Materials, vol. 40, no. 6, pp. 1457-1460, 2011.

Download

Manuscript (pdf)
Copyright notice: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author’s copyright. These works may not be reposted without the explicit permission of the copyright holder.

Abstract

We report on the characterization of gettered p-type GaP substrates for application in high-efficiency multijunction solar cells. A commercial zinc-doped GaP substrate was divided, with one piece soaked in a phosphorus-saturated gallium-aluminum melt at 975C. Low-temperature continuous-wave photoluminescence indicated a significant decrease in deep-level impurity peaks due to oxygen and zinc-oxygen complexes after gettering in the phosphorus-saturated gallium-aluminum melt. To illustrate what effect this has on minority-carrier diffusion lengths, Au/GaP Schottky solar cells were fabricated on the substrates, and the spectral response of each was examined. A marked increase in response across all wavelengths on the gettered sample indicates an increase in minority-carrier diffusion lengths. To ensure these results were not simply due to an increase in the depletion region width resulting from a change in carrier density, C–V profiling was performed and found only a small change in carrier concentration of the gettered sample.

Keywords

Gettering, GaP, multijunction solar cell, photoluminescence, spectral response, capacitance–voltage

DOI

10.1007/s11664-011-1605-1

Citation

K. H. Montgomery, C. R. Allen, I. H. Wildeson, J-H. Jeon, A. K. Ramdas, J. M. Woodall, “Gettered GaP Substrates for Improved Multijunction Solar Cell Devices,” Journal of Electronic Materials, vol. 40, no. 6, pp. 1457-1460, 2011.