An extendible beyond 20% efficiency cost-efficient bifacial cell using boron & phosphorus implantation technology and its prospects for the future production

This paper presents an extendible beyond 20% efficiency cost-efficient roadmap for bifacial solar cell, which is suitable to both p-type and n-type substrate. The roadmap is based on boron & phosphorus implantation and screen print technology. We experimentally demonstrate here bifacial cells using industrial p-type c-Si substrate with front side efficiency of 20% and rear side efficiency of 16-16.5%. Due to the bifacial generation of electricity, these cells are expected to perform at high effective efficiency under various environments with different ground reflectance. Furthermore, very high quality boron implanted emitter with emitter saturation current as low as 5E-15 Acm-2 and open circuit voltage above 655 mV was obtained, which demonstrates the potential of implantation technology for the production of also other high efficiency cell architectures.