The influence of substrate temperature on electrical properties of Cu/CdS/SnO2 Schottky diode


TOMAKİN M., Altunbas M., BACAKSIZ E.

PHYSICA B-CONDENSED MATTER, vol.406, no.23, pp.4355-4360, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 406 Issue: 23
  • Publication Date: 2011
  • Doi Number: 10.1016/j.physb.2011.08.067
  • Title of Journal : PHYSICA B-CONDENSED MATTER
  • Page Numbers: pp.4355-4360

Abstract

Polycrystalline CdS samples on the SnO2 coated glass substrate were obtained by vacuum evaporation method at low substrate temperatures (T-s=200 and 300 K) instead of the commonly used vacuum evaporation at high substrate temperatures (T-s > 300 K). X-ray diffraction studies showed that the textures of the films are hexagonal with a strong (0 0 2) preferred direction. Circular Cu contacts were deposited on the upper surface of the CdS thin films at 200 K by vacuum evaporation. The effects of low substrate temperature on the current-voltage (I-V) characteristics of the Cu/CdS/SnO2 structure were investigated in the temperature range 100-300 K. The Cu/CdS (at 300 K)/SnO2 structure shows exponential current-voltage variations. However, I-V characteristics of the Cu/CdS (at 200 K)/SnO2 structure deviate from exponential behavior due to high series resistance. The diodes show non-ideal I-V behavior with an ideality factor greater than unity. The results indicate that the current transport mechanism in the Cu/CdS (at 300 K)/SnO2 structure in the whole temperature range is performed by tunneling with E-00=143 meV. However, the current transport mechanism in the Cu/CdS (at 200 K)/SnO2 structure is tunneling in the range 200-300 K with E-00=82 mev. (C) 2011 Elsevier B.V. All rights reserved.