Enhancement of electrical performance of acid textured multi crystalline silicon solar cells

Abstract

Multicrystalline silicon (mc-Si) material is a promising alternative to monocrystalline CZ silicon because of its lower cost. Solar cell industries are investing in the improvement of electrical performance of mc-Si to make it competitive in the solar cell market. To improve the absorption of incident light, an isotropic texture using nitric acid (HNO 3 ), hydrofluoric acid (HF) and demineralized (i.e. dionized) water (DI H 2 O) is widely used but leads to etch pits at the grain boundary. In this research work, the formation of etch pits and its impact on the electrical performance of the solar cell has been analyzed. In addition, phosphorus diffusion temperature, phosphorus concentration, coating thickness (CT), refractive index (RI) of the anti reflection coating (ARC), and sintering speed of metal electrodes have been investigated. A batch of 156 mm2(SQ) is fabricated with 16.54% average cell efficiency which is 0.42%absolute higher and the shunt resistance (R sh ) is increased by two fold compared to the standard process. The surface morphology, reflectance factor (RF), open circuit voltage (V oc ), short circuit current (I sc ), fill factor (FF), and cell efficiency (η) have been analyzed and compared also with the standard process.