Electrodeposition of In:CdSe precursor thin films in aqueous electrolytes including different selenous acid concentrations as Se source


Degdas G., Peksoz A.

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING, vol.104, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 104
  • Publication Date: 2019
  • Doi Number: 10.1016/j.mssp.2019.104655
  • Journal Name: MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Electrodeposition, In:CdSe thin film, n-type semiconductor, II-VI compounds, Hall-effect, ELECTRICAL-PROPERTIES, OPTICAL-PROPERTIES, CDSE
  • Bursa Uludag University Affiliated: Yes

Abstract

In:CdSe precursor thin films were electrochemically grown on indium fin oxide (ITO) coated glass substrates at a constant potential of -0.95 V vs. Ag/AgCl reference electrode. Deposition solutions were composed of 10 mM CdCl2, 10 mM InCl3, 5-10 mM H2SeO3 as precursors, and 200 mM LiCl. The concentration of Se source (H2SeO3) was increased from 5 mM to 35 mM by a step of 5 mM. HCl was used for pH adjustment of the electrolytes. The uniform thin films are characterized by SEM-EDX, XRD, UV-VIS and Hall-Effect measurements. SEM studies show that the surface formations of In:CdSe deposits change depending on the Se content. For all deposits, XRD analyses confirm the formation of CdIn2S4 with a tetragonal crystalline phase. Energy band gap of the films is calculated from Tauc equation using UV-VIS absorbance spectra. Energy band gaps are found to be between 1.98 eV and 2.23 eV. Hall-Effect measurements show all deposits exhibit n-type semiconductor character. The donor density changes between -1.3 x 10(17) cm(-3) and -4.1 x 10(18)cm(-3). The conductivity of the In:CdSe thin films decreases from 73.2 (Omega cm)(-1) to 24.2 (Omega cm)(-1) as the Se atomic percentage in the film increases. The mobility of the films increases with the increasing of Se atomic percentage.