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Charge Collection Characterization of Polycrystalline n-GaAs Layers for Solar Cells

Published online by Cambridge University Press:  15 February 2011

O. Paz
Affiliation:
IBM East Fishkill, General Technology Division, Hopewell Junction, NY 12533
K. N. Bhat
Affiliation:
Electrical and Systems Eng. Dept., Rensselaer Polytechnic Institute, Troy, NY 12181
J. M. Borrego
Affiliation:
IBM East Fishkill, General Technology Division, Hopewell Junction, NY 12533
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Abstract

N–type Ga-As polycrystalline layers, grown on Mo substrates by the metal-organic process were investigated using the SEM. Micrographs of charge collection contrast indicate a fairly random distribution of high collection (bright) grains. In a typical cell about 1/3 of its area is bright, with nonuniformities in collection current within and between grains. These results correlate well with Isc measurements, and some of the variations betweencells is explained in terms of insufficient doping of the grain boundaries.

Reducing the penetrating depth of the carriers' excitation volume results in lowering of the collection current. The measurements were normalized for changes in beam and EBIC current by a comparison with a single crystal cell of the same geometry. This degradation is explained in terms of contamination or damage of the layer close to the surface during growth.

Type
Research Article
Copyright
Copyright © Materials Research Society 1982

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References

REFERENCES

1. Blakeslee, A. E. and Vernon, S. M., IBM J. Res. Development, 22, No. 4, July 1978, p. 346.Google Scholar
2. Dapkus, P. D. et al. , Conf. Rec. 13th IEEE Photovoltaic Specialists Conference, Washington, D.C., June 1978, p. 960.Google Scholar
3. Chu, S. S., Chu, T. L. and Lee, Y. T., IEEE Trans. Electron Devices, Vol. ED27, pp. 640645, (1980).Google Scholar
4. Weiner, A. S. et al. , IEEE Trans. Electron Devices, Vol. ED27, pp. 22812285, (1980).Google Scholar
5. Pande, K., Reep, D., Srivastava, A., Tiwari, S., Borrego, J. M. and Ghandi, S. K., J. Electrochem. Soc., 126, 300, (1979).CrossRefGoogle Scholar
6. Pande, K. P. et al. , IEEE Trans. Electron Devices, Vol. ED27, pp. 635640, (1980).Google Scholar
7. Leamy, H. J., Kimerling, L. C. and Ferris, S. D., Scanning ElectronMicroscopy/1978/I, O. Johari (ed.) SEM, Inc., AMF O'Hare, IL, 60666, pp. 717–726.Google Scholar
8. Wittry, D. B. and Kyser, D. F., J. Appl. Phys. 36, 1387, (1965).Google Scholar
9. ‘Stereoscan’ S4 Scanning Electron Microscope, Cambridge Scientific Instruments Limited (1971).CrossRefGoogle Scholar
10. Matsukawa, T. M. et al. , J. Appl. Phys., 45, 733, (1974).Google Scholar
11. Borrego, J. M. et al. , submitted for publication.Google Scholar
12. Seto, J. Y. W., J. Appl. Phys. 46, 5247 (1975).Google Scholar
13. Seager, C. H. and Ginely, D. S., J. Appl. Phys. 52, 1050 (1981).Google Scholar
14. Loferski, J. J., Conf. Rec. of the International Electron Devices Meeting, Washington, D.C., December, 1979, p. 426.Google Scholar