Employing zinc oxide-tantalum pentoxide blend coatings as eminent light harvester for improving performance of silicon solar cell

Optically transparent zinc oxide and tantalum pentoxide thin surface films were deposited on front surface of polycrystalline silicon solar cell in the presence of room temperature for minimizing the incident light reflection. The deposition may be performed through vacuum or non-vacuum-based coating techniques. In this current research work, radio frequency sputter deposition technique was adopted for achieving uniform surface coatings such as zinc oxide (ZnO), tantalum pentoxide (Ta₂O₅) and zinc oxide-tantalum pentoxide blends (ZnO-Ta₂O₅). Antireflective surface coatings enhance light transmission and improve the power conversion efficiency of solar cells. The coated and uncoated solar cells were analysed to study the structural, optical, electrical, morphological and thermal characteristics. The existence of ZnO, Ta₂O₅ and ZnO-Ta₂O₅ blends were confirmed by matching the standard diffraction pattern with the obtained X-ray diffraction (XRD) data. The average crystallite size determined from obtained XRD analysis was 24.15 nm. ZnO (G1), Ta₂O₅ (G2) and ZnO-Ta₂O₅ blends (G3) were coated over solar cell under optimal sputter coating time of 45 min. ZnO-Ta₂O₅ blend-coated solar cell (G3) exhibited maximum photocurrent and voltage generation of J_sc = 36.9 mA cm^-2 , V_oc = 0.666 V (under direct sunlight) and J_sc = 40.02 mA cm^-2 and V_oc = 0.671 V (under simulated light source). Through field-emission scanning electron microscopy (FESEM) analysis, cross-sectional thickness of various samples were identified as 0.55, 0.61 and 0.63 lm. From experimental results, the blend-coated solar cell (G3) was found to be promising antireflective coatings for multicrystalline Si solar cells. Neodymium light was significant in replicating consistent solar radiation, especially for promoting growth in green plants and domestic animals. (author)