Synthesis and optical characterization of Mn-doped ZnS nanocrystalline thin films prepared via chemical bath deposition

TL;DR

This study reports the synthesis of Mn-doped ZnS nanocrystalline thin films via chemical bath deposition, analyzing their structural and optical properties, and demonstrating potential for optoelectronic applications.

Contribution

It introduces a low-temperature chemical bath method for Mn-doped ZnS thin films and characterizes their optical modifications due to doping.

Findings

Nanocrystalline cubic ZnS with ~37 nm size formed.

Films exhibit high visible transparency and a band gap of ~3.70 eV.

Mn doping causes a red shift in absorption edge, altering optical properties.

Abstract

Manganese-doped zinc sulfide nanocrystalline thin films were synthesized using a low-temperature chemical bath deposition and deposited on glass substrates for controlled durations using triethanolamine (TEA) as a complexing and capping agent. After deposition, the films were annealed at 200 degrees Celsius and characterized by X-ray diffraction (XRD), SEM, and UV-Vis spectroscopy. XRD patterns confirmed the formation of nanocrystalline cubic zinc blende ZnS with an average crystallite size of approximately 37 nm. Optical measurements revealed strong transparency in the visible region, blue-shifted absorption edges due to quantum confinement, and a band gap value of approximately 3.70 eV. Mn incorporation resulted in a slight red shift of the absorption edge, attributed to particle growth and sp-d exchange interactions. These results demonstrate that Mn doping modifies the optical response of ZnS while preserving its crystalline structure, suggesting its suitability for optoelectronic and photovoltaic applications.