Study and analysis of the morphological, elemental and electrical properties of phosphorus doped monocrystalline silicon solar cell

Abstract

In this study, the impact of diffusion time on monocrystalline silicon solar cell has been analysed morphologically, elementally, and electrically by adjusting diffusion time to establish optimized properties for high-efficiency. P-type raw wafers were prepared for diffusion following cleaning and wet etching operation. POCl3 diffusion was done by varying diffusion time with a constant flow rate of process gases. The morphological and elemental studies were carried out with scanning electron microscope (SEM), and energy dispersive x-ray spectroscopy (EDX) respectively. Four-point probe test and Hall Effect measurement were used for studying the electrical characteristics (sheet resistance, resistivity, conductivity, and bulk concentration). From SEM result analysis, noticeable structural damages were found with the increase of doping time. Surface reflectance measurement (SRM) also supported the morphological distortion. Phosphorus, oxygen, silicon, and boron were traced by EDX analysis. The formation of phosphosilicate glass (PSG), as well as the depth of emitter, has been confirmed from the elemental analysis. The emitter length was varied from 2.5 μm to 9 μm. 5 min doped sample showed minimum surface deformation with maximum light absorbance. An acceptable sheet resistance with a compatible conductivity, mobility, and bulk concentration are also found for 5 min diffusion, which could potentially lead to high-efficient solar cell fabrication.