The effect of adding an active layer to the structure of a-Si: H solar cells on the efficiency using RF-PECVD

In this study, we report for the first time that the addition of an intrinsic layer to the a-Si: H p–i–n solar cell structure greatly enhances the conversion efficiency. The a-Si: H p–i–n solar cells were grown using Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques on the Indium Tin Oxide (ITO) substrate and added an intrinsic layer with the p–i₁–i₂–n structure to prevent sunlight energy from being absorbed the first intrinsic layer can be absorbed by the second intrinsic layer. The a-Si: H p–i–n and p–i₁–i₂–n solar cells were characterized, including optical properties, electrical properties, surface morphology, thickness, and band gap using Ellipsometric Spectroscopy (ES). Furthermore, from the optical constant and thin film thickness, the reflectance and transmittance of each sample were obtained. The p–i–n and p–i₁–i₂–n samples show good transparency in the infrared region, and this transparency decreases in the visible light region and shows an interference pattern with a sharp decrease in the transmission at the absorption edge and the performance of solar cells (curve I–V) measured by the use of sun simulator and sunshine. Our results indicate that there is a very good improvement in the efficiency of solar cells a-Si: H p–i₁–i₂–n amounting to 8.86% from the original p–i–n structure of 5.61%.