Over 19.5% n-Type Bifacial Solar Cells with Screen-Printed Boron Emitter

Abstract

The interest of using n-type silicon and producing bifacial silicon solar cells is still alive because of the potential for higher efficiency and improved solar cell power generation. In order to use n-type material for bifacial silicon solar cells, one of the challenges is the formation of p-type emitters by boron diffusion. Developing of costeffective, simple and industry-friendly alternative procedures for the solar cell industry is becoming more crucial. In this work, screen-printable boron diffusion paste was introduced and adapted to the solar cell fabrication process and n-type bifacial solar cells with screen-printed boron emitters were fabricated on large-area CZ-Si wafers. Boron diffusion was performed at around 975oC for 20 min. The best conversion efficiency of up to 19.5% was achieved with the electrical properties of 642 mV, 38.2 mA/cm2 and 79.5 for Voc, Jsc and FF, respectively. Process is still under optimization and better results are expected.