Surface coatings of zinc oxide–tantalum pentoxide on multicrystalline Si solar cell as effective light harvester

Abstract

One of the key elements to enhance the performance of solar cells was antireflective surface coatings. It can be employed through different deposition techniques such as spin coating, dip coating, blade coating, etc., In this research work, the coating materials such as ZnO, Ta₂O₅ and ZnO–Ta₂O₅ blends were coated over silicon solar cells through electrospraying technique. The performance of coated solar cells were evaluated using different characterization techniques. At the coating time of 90 min and input voltage supply of 17 kV, almost uniform thin films were attained. This was confirmed through FESEM and AFM analysis. The transmittance and power output characteristics of coated glass slides and Si solar cells were examined through UV–Vis spectroscopy and I–V source meter. In comparison with other solar cells, the ZnO–Ta₂O₅ blend (H3) coated cell exhibit uniform layer deposition and minimal light reflectance of 5%. The maximum power conversion efficiency was achieved for H3 solar cell of 17.7% (direct sunlight) and 19.6% (neodymium light source), due to increased transmittance of photons reaching the depletion region. The electrical resistivity of H3 solar cell was noted as 3.57 × 10⁻³ Ω cm using four probe method, which was lesser than other solar cells. From the obtained experimental outcomes, ZnO–Ta₂O₅ blend coated solar cell reveal the maximum performance than other coated and uncoated solar cells. Hence, ZnO–Ta₂O₅ blends were found to be better antireflective material for attaining maximum output performance of solar cell.