Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells

Ana Kanevce, Tao Song, James Sites

Research output: Contribution to conferencePaperpeer-review

10 Scopus Citations


Traditional polycrystalline CdTe solar cell performance is limited by recombination at the grain boundaries, low carrier density (p), compensation from impurities, and a low minority carrier lifetime (τ). The maximum values for these critical parameters in polycrystalling devices are p < 1015 cm-3 and τ ∼ 10 ns with open-circuit voltage (VOC) ∼ 900 mV and η ∼ 20%. Epitaxial CdTe with high-quality, low defect-density, and high carrier density, could yield a higher-efficiency PV device. Using numerical simulation, we investigate the combined effects of minority carrier lifetime τ (0.1 - 500 ns) and carrier density p (1×1014 - 5×1018 cm-3) on device performance, predicting obtainable performance of VOC > 1100 mV and η > 25% for high τ and high p. While the VOC is strongly affected by both p and τ, the short-circuit current (JSC) is mainly dependent on the lifetime τ and absorption losses in the front contact stack. In addition, increasing the thickness of p-CdTe (varied from 0.5 - 20 μm) at different τ (1 - 100 ns) shows an improvement in JSC due to increased long-wavelength photon collection and then saturates for thicker p-CdTe. In some cases, the cell performance is compromised by the presence of a significant back-contact barrier Φb. The simulated results show that the cell performance is not strongly affected until Φb exceeds 0.4 eV.

Original languageAmerican English
Number of pages4
StatePublished - 15 Oct 2014
Event40th IEEE Photovoltaic Specialist Conference, PVSC 2014 - Denver, United States
Duration: 8 Jun 201413 Jun 2014


Conference40th IEEE Photovoltaic Specialist Conference, PVSC 2014
Country/TerritoryUnited States

Bibliographical note

Publisher Copyright:
© 2014 IEEE.

NREL Publication Number

  • NREL/CP-5J00-61391


  • device modeling
  • epitaxial CdTe
  • solar cells


Dive into the research topics of 'Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells'. Together they form a unique fingerprint.

Cite this