Manganese-doped zinc sulfide nanocrystalline thin films hold promise for next-generation optoelectronic and photovoltaic devices, and researchers are actively exploring methods to optimise their properties. Himal Pokhrel from The University of Memphis and Urvashi Verma from Sardar Patel University, along with their colleagues, successfully synthesised these films using a low-temperature chemical bath deposition technique. The team demonstrates that incorporating manganese modifies the optical characteristics of zinc sulfide while maintaining its crystalline structure, resulting in strong visible light transparency and a tunable band gap. This achievement represents a significant step towards creating more efficient and versatile materials for a range of applications, including solar cells and light-emitting diodes, by offering a pathway to control the optical properties of nanocrystalline thin films.
Structural analysis confirmed a cubic zinc blende structure with an average crystallite size of approximately 37nm. Optical measurements demonstrated strong transparency in the visible range for undoped films, while manganese doping and increased deposition time led to a reduction in transmittance. Films displayed blue-shifted absorption edges and widened band gaps, indicative of quantum confinement effects, with band gap values reaching up to 3.
7 eV. Manganese incorporation caused a slight red shift in the absorption edge and a reduction in the band gap, attributed to increased particle size and interactions between manganese and zinc atoms. This research demonstrates that manganese doping effectively modifies the structural and optical behaviour of zinc sulfide thin films while maintaining their crystalline integrity. These synthesised films show promise for applications in optoelectronic and photovoltaic devices, and deposition time proves crucial in influencing the electronic structure and optical transitions within the films. This work establishes a pathway for tailoring manganese-doped zinc sulfide nanocrystalline thin films to achieve desired optical properties for various technological applications.
Manganese-Doped Zinc Sulfide Thin Film Synthesis
Scientists engineered a low-temperature chemical bath deposition method to synthesise manganese-doped zinc sulfide nanocrystalline thin films on glass substrates, carefully controlling deposition duration and utilising triethanolamine as a complexing and capping agent. Thorough cleaning of glass substrates, involving hydrochloric acid immersion, detergent washing, and acetone rinsing, preceded film growth, ensuring improved adhesion and uniform film formation. The team prepared solutions of zinc acetate and manganese acetate, precisely calculating the manganese concentration to achieve 4 mol% doping. A thiourea solution was also prepared and combined with the zinc and manganese solutions, along with triethanolamine, forming a complex that controlled the release of zinc ions.
The pH of the mixture was then adjusted before immersing cleaned glass substrates into the reaction bath maintained at 70°C. Thin films were deposited for durations of 1, 1. 5, and 2 hours, after which the substrates were rinsed, dried, and annealed to enhance crystallinity. The formation of manganese-doped zinc sulfide nanocrystals proceeded through controlled dissociation, complexation, and precipitation reactions, where zinc and manganese ions combined with sulfide ions to form the desired nanocrystalline films. This method enables precise control over film composition and structure, paving the way for advanced optoelectronic and photovoltaic applications.
Manganese Doping Enhances Zinc Sulfide Transparency
Scientists successfully synthesised manganese-doped zinc sulfide nanocrystalline thin films using a low-temperature chemical bath deposition technique. Structural analysis confirmed the films exhibited a cubic zinc blende crystal structure with an average crystallite size of approximately 37nm. Optical measurements revealed strong transparency in the visible region and a blue-shifted absorption edge, indicative of quantum confinement effects, with a band gap value of approximately 3. 70 eV. The incorporation of manganese resulted in a slight red shift of the absorption edge, attributed to particle growth and the interaction between manganese and zinc atoms within the material.
These results demonstrate that manganese doping effectively modifies the optical response of zinc sulfide while preserving its crystalline structure. The team measured a quantifiable shift in the absorption edge, confirming the influence of manganese on the material’s electronic properties. The synthesised films exhibit characteristics suitable for optoelectronic and photovoltaic applications, offering a potential alternative to cadmium sulfide in solar cell technologies. This research delivers a cost-effective and low-temperature method for producing these films, paving the way for scalable production and wider implementation in various devices. The team’s work confirms the potential of manganese-doped zinc sulfide as a promising material for future semiconductor applications, offering both performance and environmental benefits.
Manganese Doping Modifies Zinc Sulfide Optics
Manganese-doped zinc sulfide nanocrystalline thin films were successfully created using a low-temperature chemical bath deposition technique. Characterisation confirmed the formation of cubic zinc blende structured zinc sulfide crystals with an average size of approximately 37 nanometres. Optical measurements demonstrated strong transparency in the visible spectrum for the undoped films, while manganese incorporation resulted in a slight shift in the absorption edge. This red shift is attributed to both particle growth and interactions between the manganese dopant and the electronic structure of the zinc sulfide.
These findings demonstrate that manganese doping effectively modifies the optical properties of zinc sulfide thin films while maintaining their crystalline structure. The observed changes in the absorption edge and transparency suggest potential applications in optoelectronic and photovoltaic devices. This work establishes a foundation for developing novel materials with tailored optical characteristics for a range of technological applications.
👉 More information
🗞 Synthesis and optical characterization of Mn-doped ZnS nanocrystalline thin films prepared via chemical bath deposition
🧠ArXiv: https://arxiv.org/abs/2511.16167