Response of CdS/CdTe devices to Te exposure of back contact

T. A. Gessert, J. M. Burst, J. Ma, S. H. Wei, D. Kuciauskas, T. M. Barnes, J. N. Duenow, M. R. Young, W. L. Rance, J. V. Li, P. Dippo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Theoretical predictions of thin-film CdS/CdTe photovoltaic (PV) devices have suggested performance may be improved by reducing recombination due to Te-vacancy (VTe) or Te-interstitial (Tei) defects. Although formation of these intrinsic defects is likely influenced by CdTe deposition parameters, it also may be coupled to formation of beneficial cadmium vacancy (VCd) defects. If this is true, reducing potential effects of VTe or Tei may be difficult without also reducing the density of VCd. In contrast, post-deposition processes can sometimes afford a greater degree of defect control. Here we explore a post-deposition process that appears to influence the Te-related defects in polycrystalline CdTe. Specifically, we have exposed the CdTe surface to Te prior to ZnTe:Cu/Ti contact-interface formation with the goal of reducing VTe but without significantly reducing VCd. Initial results show that when this modified contact is used on a CdCl2-treated CdS/CdTe device, significantly poorer device performance results. This suggests two things: First, the amount of free-Te available during contact formation (either from chemical etching or CuTe or ZnTe deposition) may be a more important parameter to device performance than previously appreciated. Second, if processes have been used to reduce the effect of VTe (e.g., oxygen and chlorine additions to the CdTe), adding even a small amount of Te may produce detrimental defects.

Original languageEnglish
Title of host publicationProgram - 38th IEEE Photovoltaic Specialists Conference, PVSC 2012
Number of pages5
Publication statusPublished - 2012 Nov 26
Event38th IEEE Photovoltaic Specialists Conference, PVSC 2012 - Austin, TX, United States
Duration: 2012 Jun 32012 Jun 8

Publication series

NameConference Record of the IEEE Photovoltaic Specialists Conference
ISSN (Print)0160-8371


Other38th IEEE Photovoltaic Specialists Conference, PVSC 2012
Country/TerritoryUnited States
CityAustin, TX

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'Response of CdS/CdTe devices to Te exposure of back contact'. Together they form a unique fingerprint.

Cite this