PROCESSING AND CHARACTERISATION OF ISOTROPICALLY, ALKALINE AND MECHANICALLYTEXTURED MC-Si BURIED CONTACT SOLAR CELLS: A COMPARATIVE STUDY

摘要

The mechanical, optical and electrical properties of isotropically, alkaline and mechanically textured BuriedContact Solar Cells (BCSC) are discussed in this work. The mechanical stability of isotropically textured wafers and BCSCs are studied using a twist tester and the wafer stability is analysed in terms of wafer fracture force and wafer flexibility. The increased stability of wafers after isotropically texturing is maintained throughout the BCSC process, even after different high temperature processes. The optical properties are investigated using the optical transmission and reflection measurements analysis. The optical path length of isotextured wafers is analysed by means of simulated transmission curveusing the absorption coefficient extracted from transmission measurement of an alkaline textured wafer. The isotextured cells exhibit lower reflectance in the high wavelength range whereas the mechanically textured cells exhibit lower reflectance in the short wavelength region. Higher short circuit current density has been measured on mechanically textured BCSC in comparison to isotropically textured and alkaline textured BCSC that could be attributed to the light trapping in the short wavelength range.