Synthesis and characterization of novel yttrium-incorporated copper selenide (CuSe:Y) thin materials for solar energy applications

Undoped and Y-doped CuSe with different dopant concentration (0.01–0.04 mol%) have been successfully synthesized using selenium (IV) oxide (SeO₂), copper (II) sulfate pentahydrate (CuSO₄⋅5H₂O), and yttrium as sources of Cu²⁺, Se²⁻, and Y³⁺ ions, respectively, on glass slides via spray pyrolysis method. The impact of yttrium doping on the structural, compositional, morphological, electrical, and optical properties of CuSe were studied using X-ray diffractormeter, Scanning electron microscopy-SEM, Energy dispersive X-ray spectroscopy-EDX, four-point probe, and 756S UV–Visible spectrophotometer accordingly. The XRD result reveals that the deposited thin materials exhibited a polycrystalline cubic structure with preferred orientation along (200), while the EDX result affirms the existence of the fundamental elements deposited. The electrical studies result supported the fact that the thin films are semiconductors. The optical results revealed high absorbance, low transmittance, and narrowed energy band gap of CuSe films after adding yttrium dopant. Undoped CuSe recorded an energy band gap value of 3.0 eV which experienced a declined range from 2.81 to 2.50 eV upon Y doping. Addition of Y dopant was seen to improve the crystallinity of the films and narrowed the energy band gap of undoped CuSe, thereby boosting the performance of YCuSe for use as photovoltaic material and also a more reliable material for absorber layer in solar energy collection.