Prospects of thickness reduction of the CdTe layer in highly efficient CdTe solar cells towards 1 μm

Nowshad Amin, Takayuki Isaka, Tamotsu Okamoto, Akira Yamada, Makoto Konagai

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

This study focuses on the technique for the stable growth of CdTe (1.44eV) with thickness near its absorption length, 1 μm, by close spaced sublimation (hereafter CSS) process, in order to achieve high conversion efficiency. X-ray diffraction (XRD) spectroscopy was carried out to examine the microstructure of the films. Current-voltage (I-V) characteristics, spectral response and other features of the solar cells using these CdTe films were investigated to elucidate the optimum conditions for achieving the best performance in such thin (1 μm) CdTe solar cells. Thickness was found to be reduced by controlling the temperature profile used during CSS growth. The temperature profile was found to be an important factor in growing high-quality thin films. By controlling the growth parameters and optimizing the annealing temperature at different fabrication steps, we have succeeded, to date, in achieving cell efficiencies of 14.3% (open-circuit voltage (Voc): 0.82 V, short-circuit current (Jsc): 25.2mA/cm2, fill factor (F.F.): 0.695, area: 1 cm2) with 5 μm, 11.4% (Voc 0.77 V, Jsc: 23.7 mA/cm2, F.F.: 0.63, area: 1 cm2) with 1.5 μm and 11.2% (Voc: 0.77V, JSC: 23.1 mA/cm2, F.F.: 0.63, area: 1 cm2) with only l μm of CdTe layer thickness at an air mass of 1.5 without antireflection coatings. This is important for establishing a strong foundation before developing a new structure (e.g., glass/ITO/CdS/CdTe/ZnTe/Ag configuration) with a back surface field of wide-bandgap material (e.g., ZnTe).

Original languageEnglish
Pages (from-to)4666-4672
Number of pages7
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume38
Issue number8 B
Publication statusPublished - 15 Aug 1999
Externally publishedYes

Fingerprint

Solar cells
solar cells
temperature profiles
ITO glass
Antireflection coatings
Sublimation
Open circuit voltage
Short circuit currents
Temperature
Conversion efficiency
antireflection coatings
air masses
Energy gap
short circuit currents
ITO (semiconductors)
open circuit voltage
spectral sensitivity
sublimation
Spectroscopy
Annealing

Keywords

  • CdTe
  • CSS process
  • Solar cells
  • Temperature profiles

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Prospects of thickness reduction of the CdTe layer in highly efficient CdTe solar cells towards 1 μm. / Amin, Nowshad; Isaka, Takayuki; Okamoto, Tamotsu; Yamada, Akira; Konagai, Makoto.

In: Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, Vol. 38, No. 8 B, 15.08.1999, p. 4666-4672.

Research output: Contribution to journalArticle

Amin, Nowshad ; Isaka, Takayuki ; Okamoto, Tamotsu ; Yamada, Akira ; Konagai, Makoto. / Prospects of thickness reduction of the CdTe layer in highly efficient CdTe solar cells towards 1 μm. In: Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers. 1999 ; Vol. 38, No. 8 B. pp. 4666-4672.
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