Effect of Co and Sn co-doping on tailoring the properties of CuO to enhance the absorption capacity of solar absorber layers
摘要
To enhance the performance of the solar absorber layer, Co-doped and (Co, Sn) co-doped Cupric Oxide (CuO) layers with varying Cobalt (Co) and Tin (Sn) ratios have been fabricated using a spin coating technique. After annealing, the films were characterized by using different techniques to examine the crystal structure, surface morphology, optical, and electronic properties, respectively. X-ray diffraction (XRD) results confirm that all fabricated thin layers have a polycrystalline monoclinic arrangement. The average crystallite size increases from 29 to 31 nm for (Co, Sn): CuO layers. Scanning electron microscopy (SEM) analysis reveals that the surface of the CuO layer transforms from a nano-ribbon to spherical nanoparticles upon the addition of (Co, Sn) with CuO layers. All CuO samples exhibit significant absorption of solar light in the visible spectrum, and the (Co, Sn): CuO layer shows an absorption coefficient (> 105 cm−1). After Co and Sn co-doping with CuO, the energy gap value altered from 1.74 to 1.48 eV. Hall effect measurement demonstrated that the pure CuO conductivity group changes from p-group to n-group upon Co doping, but in the (Co, Sn): CuO film, the conductivity type of CuO was restored. We obtained the lower resistivity of 20.5 Ω·cm and the maximum carrier concentration of 1.05 × 1017 cm−3, respectively, for (3 at.% Co + 1 at.% Sn): CuO layer. Therefore, (3 at.% Co + 1 at.% Sn): CuO layers could be an excellent potential contender for solar absorber surface and optoelectronic purposes.