Electrical and optical characterization of CdTe solar cells with CdS and CdSe buffers - A comparative study

Md Dalim Mia, Craig H. Swartz, Sanjoy Paul, Sandeep Sohal, Corey R. Grice, Yanfa Yan, Mark Holtz, Jian V. Li

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A study is reported comparing the electrical and optical properties of CdTe solar cells, prepared using CdS and CdSe buffer layers, to investigate defects in the bulk and interface, carrier transport, and recombination. Temperature dependent capacitance-voltage measurement and admittance spectroscopy were used to extract carrier concentration, resistivity, charge carrier mobility, and their temperature dependence. The authors identify the presence of two defect signatures corresponding to carrier freeze-out and the formation of a Schottky back-contact barrier. The back-contact barrier height (≈300 meV) extracted from the temperature dependent current density-voltage (JVT) experiment was confirmed by conventional admittance spectroscopy. The activation energies of mobility (resistivity) are 101.2 ± 2.5 meV (92.6 ± 2.3 meV) and 84.7 ± 2.7 meV (77.6 ± 4.5 meV) for CdS and CdSe buffer layers, respectively. Intensity dependent photoluminescence analysis demonstrates that the CdSe/CdTe device exhibits lower radiative efficiency than the CdS/CdTe device. This confirms the presence of higher defects in the CdSe/CdTe device corroborated by temperature dependent VOC analysis. The comparative electrical and optical analysis provides insight into improving the performance of CdTe solar cell device by selenization.

Original languageEnglish
Article number052904
JournalJournal of Vacuum Science and Technology B: Nanotechnology and Microelectronics
Volume36
Issue number5
DOIs
Publication statusPublished - 2018 Sep 1

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering
  • Materials Chemistry

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