Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-23T21:02:33.857Z Has data issue: false hasContentIssue false

Growth of Metamorphic InGaP for Wide-Bandgap Photovoltaic Junction by MBE

Published online by Cambridge University Press:  01 February 2011

John Simon
Affiliation:
john.simonnavas@yale.edu, Yale University, Electrical Engineering, New Haven, Connecticut, United States
Stephanie Tomasulo
Affiliation:
stephanie.tomasulo@yale.edu, Yale University, Electrical Engineering, New Haven, Connecticut, United States
Paul Simmonds
Affiliation:
paul.simmonds@yale.edu, Yale University, Electrical Engineering, New Haven, Connecticut, United States
Manuel J Romero
Affiliation:
manuel.romero@nrel.gov, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado, 80401-3393, United States
Minjoo Larry Lee
Affiliation:
minjoo.lee@yale.edu, Yale University, Electrical Engineering, New Haven, Connecticut, United States
Get access

Abstract

Metamorphic triple-junction solar cells can currently attain efficiencies as high as 41.1%. Using additional junctions could lead to efficiencies above 50%, but require the development of a wide bandgap (2.0-2.2eV) material to act as the top layer. In this work we demonstrate wide bandgap InyGa1-yP grown on GaAsxP1-x via solid source molecular beam epitaxy. Unoptimized tensile GaAsxP1-x buffers grown on GaAs exhibit asymmetric strain relaxation, along with formation of faceted trenches 100-300 nm deep in the [01-1] direction. Smaller grading step size and higher substrate temperatures minimizes the facet trench density and results in symmetric strain relaxation. In comparison, compressively-strained graded GaAsxP1-x buffers on GaP show nearly-complete strain relaxation of the top layers and no evidence of trenches. We subsequently grew InyGa1-yP layers on the GaAsxP1-x buffers. Photoluminescence and transmission electron microscopy measurements show no indication of phase separation or CuPt ordering. Taken in combination with the low threading dislocation densities obtained, MBE-grown InyGa1-yP layers are promising candidates for future use as the top junction of a multi-junction solar cell.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Guter, W., Schone, J., Philipps, S.P., Steiner, M., Siefer, G., Wekkeli, A., Welser, E., Oliva, E.,Bett, A.W., Dimroth, F., Appl. Phys. Lett. 94 (2009) 223504–3.Google Scholar
[2] Aiken, D., Comfeld, A., Stan, M., Sharps, P., IEEE 4th World Conference on Photovoltaic Energy Conversion 1 (2006) 838841.Google Scholar
[3] Tobïas, I., Luque, A., Progress in Photovoltaics: Research and Applications 10 (2002) 323329.Google Scholar
[4] Law, D.C., King, R., Yoon, H., Archer, M., Boca, A., Fetzer, C., Mesropian, S., Isshiki, T., Haddad, M., Edmondson, K., Bhusari, D., Yen, J., Sherif, R., Atwater, H., Karam, N., Solar Energy Materials and Solar Cells In Press, Corrected Proof (n.d.).Google Scholar
[5] Amano, C., Ando, K., Yamaguchi, M., J. Appl. Phys. 63 (1988) 28532856.Google Scholar
[6] Kim, A.Y., McCullough, W.S., Fitzgerald, E.A., J. Vac. Sci. Technol. B 17 (1999) 14851501.Google Scholar
[7] Zunger, A., Mahajan, S., Materials, Properties and Preparation (Handbook on Semiconductors) Ch. 19, illustrated edition, North Holland, 1994.Google Scholar
[8] Mori, M.J., Boles, S.T., Fitzgerald, E.A., J. Vac. Sci. Technol. A 28 (2010) 182188.Google Scholar
[9] Mori, M.J., Fitzgerald, E.A., J. Appl. Phys. 105 (2009) 013107–10.Google Scholar
[10] Steiner, M.A., Bhusal, L., Geisz, J.F., Norman, A.G., Romero, M.J., Olavarria, W.J., Zhang, Y., Mascarenhas, A., J. Appl. Phys. 106 (2009) 063525–5.Google Scholar
[11] Sang, J., Steeds, J.W., Hopkinson, M., Semicond. Sci. Technol. 8 (1993) 502508.Google Scholar
[12] Ptak, A.J., Friedman, D.J., Kurtz, S., J. Vac. Sci. Technol. B 25 (2007) 955959.Google Scholar
[13] Cheah, W.K., Fan, W.J., Wicaksono, S., Yoon, S.F., Tan, K.H., Journal of Crystal Growth 254 (2003) 305309.Google Scholar
[14] Yakimova, R., Omling, P., Yang, B.H., Samuelson, L., Fornell, J., Ledebo, L., Appl. Phys. Lett. 59 (1991) 1323.Google Scholar
[15] Cheah, W., Fan, W., Yoon, S., Tan, K., Liu, R., Wee, A., Thin Solid Films 488 (2005) 5661.Google Scholar
[16] Olson, J., McMahon, W.E., Kurtz, S., IEEE 4th World Conference on Photovoltaic Energy Conversion 1 (2006) 787790.Google Scholar
[17] Fetzer, C.M., Lee, R.T., Stringfellow, G.B., Liu, X.Q., Sasaki, A., Ohno, N., J. Appl. Phys. 91 (2002) 199.Google Scholar