Back Contact Effects on Junction Photoluminescence in CdTe/CdS Solar Cells

D. H. Levi, L. M. Woods, D. S. Albin, T. A. Gessert, D. W. Niles, A. Swartzlander, D. H. Rose, R. K. Ahrenkiel, P. Sheldon

Research output: Contribution to conferencePaperpeer-review

26 Scopus Citations

Abstract

Studies of junction photoluminescence in CdTe/CdS solar cells reveal that back-contact application produces a dramatic qualitative change in the junction PL spectrum. Prior to contact application, the spectrum has two peaks at energies of 1.508 eV and 1.45 eV, corresponding to recombination in bulk CdTe, and in a CdTeS alloy with 9% sulfur content, respectively. After contact application, the spectrum consists of a single broad peak at 1.48 eV. Previous studies have shown that the nitric-phosphoric (NP) etch used in the contact procedure produces a layer of elemental Tellurium (Te) on the CdTe surface. Our measurements utilizing Auger electron spectroscopy (AES) show that this Te layer penetrates grain boundaries down to the CdTe/CdS interface. It appears that the change in the near-junction PL spectrum is caused by a `grain boundary field effect' due to perturbations of the grain boundary conductivity and Fermi level.

Original languageAmerican English
Pages351-354
Number of pages4
DOIs
StatePublished - 1997
EventProceedings of the 1997 IEEE 26th Photovoltaic Specialists Conference - Anaheim, CA, USA
Duration: 29 Sep 19973 Oct 1997

Conference

ConferenceProceedings of the 1997 IEEE 26th Photovoltaic Specialists Conference
CityAnaheim, CA, USA
Period29/09/973/10/97

Bibliographical note

For preprint version, including full text online document, see NREL/CP-530-22971

NREL Publication Number

  • NREL/CP-520-24957

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