Electrical Characterization of Cu Composition Effects in CdS/CdTe Thin-Film Solar Cells With a ZnTe:Cu Back Contact

Author

Li, Jian V. ; Duenow, Joel N. ; Kuciauskas, Darius ; Kanevce, Ana ; Dhere, R.G. ; Young, Matthew R. ; Levi, Dean H.

Author_Institution

Nat. Renewable Energy Lab., Golden, CO, USA

Volume

3

Issue

3

fYear

2013

fDate

Jul-13

Firstpage

1095

Lastpage

1099

Abstract

We study the effects of Cu composition on the CdTe/ZnTe:Cu back contact and the bulk CdTe. For the back contact, its potential barrier decreases with Cu concentration, while its saturation current density increases. For the bulk CdTe, the hole density increases with Cu concentration. We identify a Cu-related deep level at ~0.55 eV whose concentration is significant when the Cu concentration is high. The device performance, which initially improves with Cu concentration then decreases, reflects the interplay between the positive influences (reducing the back-contact potential barrier while increasing the saturation current density of the back contact and hole density in CdTe bulk) and negative influences (increasing deep levels in CdTe) of Cu.

Keywords

II-VI semiconductors; cadmium compounds; copper; current density; deep levels; doping profiles; electrical conductivity; electrical contacts; hole density; semiconductor doping; semiconductor thin films; solar cells; wide band gap semiconductors; zinc compounds; CdS-CdTe-ZnTe:Cu; back-contact potential barrier; copper concentration; deep level; electrical property; hole density; saturation current density; thin-film solar cells; Admittance measurement; CdTe; capacitance–voltage (CV) characteristics; charge carrier density; contacts; defect;

fLanguage

English

Journal_Title

Photovoltaics, IEEE Journal of

Publisher

ieee

ISSN

2156-3381

Type

jour

DOI

10.1109/JPHOTOV.2013.2257919

Filename

6509932