Optical, Structural and Morphological Evaluation of Electrodeposited Chromium Selenide (CRSE) Thin Films

Abstract

Chromium selenide (CrSe) thin films was successfully deposited on fluorine-doped tin oxide (FTO) conducting substrates using an electrodeposition technique. The films exhibited thicknesses ranging from 71.22–166.17 nm, with thickness increasing progressively with deposition potential due to enhanced ionic transport and accelerated film nucleation. Optical characterization revealed absorbance values between 6.16–30.39%, which increased with deposition potential and decreased with increasing wavelength. Transmittance values ranged from 49.67–88.90%, showing a reverse trend, decreasing with higher deposition potentials and increasing with wavelength. The CrSe films showed low reflectance across the UV–NIR range, with values between 5.99–19.94%, and maxima occurring in the UV region. The refractive index values ranged from 1.63–2.64, decreasing with wavelength but rising with deposition potential. Extinction coefficient values were between 9.50×10⁻² – 2.01×10⁻¹, while optical conductivity ranged from 6.42×10¹³ – 50.48×10¹³ s⁻¹.Tauc analysis revealed that the energy bandgap varied with deposition potential, ranging from 3.00–3.25 eV, confirming CrSe as a wide bandgap semiconducting material suitable for optoelectronic and photovoltaic applications. XRD analysis confirmed hexagonal phase CrSe, with crystallite sizes of 30.780–33.455 nm, dislocation densities of 9.050×10¹⁴ – 1.092×10¹⁵ lines/m², and microstrains of 3.09×10⁻³ – 8.46×10⁻³. SEM micrographs showed surfaces composed of tiny agglomerated particles of irregular shapes and sizes, while EDS analysis confirmed the elemental presence of chromium and selenium. These results demonstrate that electrodeposited CrSe thin films possess desirable structural and optical characteristics for use in optoelectronic, photovoltaic, and spintronic applications.