Investigation on the electronic and physical properties of gamma-MnS films as a function of thickness


Ulutas C., Erken O., Gunes M., Ozkendir O., GÜMÜŞ C.

Materials Science in Semiconductor Processing, vol.140, 2022 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 140
  • Publication Date: 2022
  • Doi Number: 10.1016/j.mssp.2021.106412
  • Journal Name: Materials Science in Semiconductor Processing
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Applied Science & Technology Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex
  • Keywords: CBD, FE-SEM, Gamma-MnS, Optical properties, XAFS, XRD
  • Hakkari University Affiliated: No

Abstract

In this study, gamma-manganese sulphide (γ-MnS) films were prepared at various thickness and deposition time at a temperature of 50 °C by Chemical Bath Deposition Method (CBD). The characterization of the gamma-MnS films were determined by using the following methods; X-ray Absorption Fine Structure Spectroscopy (XAFS), X-ray diffraction (XRD), optical absorption, Field Emission-Scanning Electron Microscope (FE-SEM), Energy Dispersive X-ray analysis (EDX). The electronic interplay via the coupling between Mn 3d levels and S 2p levels was determined to build up strong molecular bonds containing broad band with hybrid pd levels at low energy levels. The results of the electronic structure analysis were also tested with the absorption spectroscopy calculations and high agreement is reported. XRD analysis revealed that the film deposited for 5 h had amorphous structure and turned to be crystal structure in hexagonal phase with deposition time 10, 15, 20 h due to increasing film thickness value. The optical band gap values were reduced from 3.86 eV to 3.10 eV with increasing film thickness. The average refractive index value of films at visible region were calculated between 1.55 and 2.81 as a function of increment in film thickness. The mobility and resistivity of the films were measured as 8.65–55.76 cm2/Vs and 3.10 × 105–2.39 × 106 Ωcm, respectively, by Hall measurement.