Abstract

In this paper, Glancing Angle Deposition Technique (GLAD) has been used to grow Silicon (Si) thin film by vacuum thermal method on glass substrates. Heterojunction with Intrinsic Thin-Layer (HIT) solar cells are sensitive to interface state density. Traditional texture process for silicon solar cells is not suitable for HIT one. Thus, Sodium Hydroxide (NaOH), Isopropanol (IPA) and mixed additive were tentatively introduced for the texturization of HIT solar cells in this study. Then, a mixture including nitric acid (HNO3), Hydrofluoric Acid (HF). The morphology of textured surface and the influence of etching time on surface reflectance were studied, and the relationship between etching time and surface reflectance, vertex angle of pyramid structure was analyzed. It was found that the mixture consisting of 1.1 wt% NaOH, 3 vol% IPA and 0.3 vol% additives with etching time of 60min is the best for HIT solar cells under the condition of 80 °C. By used SEM and optical properties the average surface reflectance was 11.68%. Finally the effect of different processes on the performance of HIT solar cells was investigated. Films deposited at large angles (00, 100, 200, 300, 450, 600) was found to be poly-crystalline in nature along the peak intensity direction. The surface morphology has shown an improvement without the presence of secondary phases for higher incident angles (45°). It has been observed that the use of this growth technique leads to an improvement in the optical properties of the films.

Keywords: Si; Thin films; GLAD technique; Structural properties; Optical properties; Electrical characteristics