Optical analysis of thin film cadmium telluride solar cell using nanoparticles for efficiency enhancement

To develop exceptionally effective thin film solar cells with significant cost reduction, light management with plasmonic nanoparticles has become one of the prominent solutions. The present article discusses the role of nanostructures placed as the back reflector through the numerical optical analysis and optimization study of all parameters needed to design cadmium telluride (CdTe) solar cells with only 100 nm active layer thickness. A thorough study of the absorption improvement in a CdTe thin-film solar cell with a spherical array of plasmonic metal nanoparticles is performed. It is found that the photon absorption in the active CdTe layer is considerably improved by the stimulation of localized plasmons in the metallic nanostructures. The study demonstrates that the proposed design based on periodic nanostructures outperforms the reference planar aluminum (Al) back reflector and bare cell structure in terms of optical performance. The proposed structure achieved high absorption when aluminum nanoparticles were used due to better trapping of incident photons than planar reference cell and bare cell structures. The photocurrent density measured under AM-1.5G illumination is 29.26 mA/cm2, 24.90 mA/cm2, and 10.12 mA/cm2 for cell with Al nanoparticles, planar Al back reflector, and bare cell, respectively. The results depict that the Al nanoparticles-based cell performed better in absorption and back reflection. Rigorous coupled wave analysis is used to optimize and calculate cell parameters.