Employing pre-annealing as a control tool for alloying in CdSeTe/CdTe stacks produced by evaporation in vacuum


Çiriş A., Atasoy Y., BACAKSIZ E.

Micro and Nanostructures, vol.190, 2024 (Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 190
  • Publication Date: 2024
  • Doi Number: 10.1016/j.micrna.2024.207829
  • Journal Name: Micro and Nanostructures
  • Journal Indexes: Scopus
  • Keywords: Alloying, CdSeTe/CdTe, Pre-annealing, Vacuum evaporation
  • Karadeniz Technical University Affiliated: Yes

Abstract

Alloying plays a critical role in CdSeTe/CdTe stacks used as absorber structure in high efficiency solar cells. In this study, the effect of pre-annealing between CdSeTe and CdTe on the structural and optical properties of stacks was examined in detail. After the CdSeTe layers (before CdTe) were grown by vacuum evaporation, pre-annealing was applied at moderate temperatures in the range of 200°C–300 °C. According to both XRD patterns and Raman spectra, a clear effect of pre-annealing temperature on alloying ratios and phase formations between CdSeTe and CdTe was ascertained. It was observed from the surface images that the change in pre-annealing temperature affected the grain sizes and morphology, depending on the Se ratios in the alloying. It was found that the transmission spectrum shifted to the long wavelength region with the change in crystallization as a result of pre-annealing. In the PL spectra, the presence of transitions related to the phase structures revealed by the XRD results was detected. In consequence, pre-annealing at 250 °C presented more promising results for potential CdTe cell applications.