Chalcopyrite/Si heterojunctions for photovoltaic applications

O. Akpa, S. Shoieb, T. Thompson, T. Isaacs-Smith, P. Anderson, S. Seraphin, K. Das

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Films of CuInSe 2 (CIS) and CuGaSe 2 (CGS) were deposited on (100) Si by radiofrequency (RF) magnetron sputtering from stoichiometric CIS and CGS targets. Rutherford backscattering (RBS) analysis yielded a composition of Cu 0.8In 1.1Se 1.9 for CuInSe 2, which indicates that these films were Cu and Se poor. A composition of Cu 0.3Ga 1.5Se 2.0 for CuGaSe 2 shows Ga-rich and Cu-poor layers. Transmission electron microscopy (TEM) of cross-sectional samples established that the films were polycrystalline in nature and free of pinhole defects that normally short-circuit devices fabricated on glass with submicron absorber layers. From the electron and x-ray diffraction patterns, tetragonal chalcopyrite phases of the material were identified. Circular diodes, with a diameter between 100 μm and 400 μm, were fabricated on the grown films with a common Au back-contact. Diodes on both CIS and CGS films exhibited rectifying characteristics. From the polarity corresponding to the high and low currents, it was inferred that the grown films were p-type. These diodes exhibited photovoltaic response, and the forward-bias current increased by as much as two orders of magnitude when illuminated by a 75-W halogen lamp. The open-circuit voltages (V OC) for these devices are expected to approach the turn-on voltage of the diodes, 0.5 V and 0.7 V, for the CGS/Si and the CIS/Si heterojunctions, respectively. Shunting caused by degenerate phases present in the CGS film is believed to have resulted in the observed lower turn-on voltage for the CGS/n-Si heterojunction diode.

Original languageEnglish (US)
Pages (from-to)2462-2466
Number of pages5
JournalJournal of Electronic Materials
Issue number11
StatePublished - Nov 2010
Externally publishedYes


  • Chalcopyrite
  • CuGaSe
  • CuInSe
  • Heterojunction
  • Photovoltaic
  • Sputtering

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry


Dive into the research topics of 'Chalcopyrite/Si heterojunctions for photovoltaic applications'. Together they form a unique fingerprint.

Cite this