A Passivated Rear Contact for High-Efficiency n-Type Si Solar Cells Enabling High Voc's and FF>82 %

Due to the improvements in material quality and surface passivation, high-efficiency solar cells are often limited by the recombination at the metal semiconductor contacts. As a solution to this problem, Swanson proposed “to put a heterojunction with a band-gap larger than silicon between the metal and silicon”[1] also known as passivated contact. In this work, a tunnel oxide passivated contact (TOPCon) structure allowing both an excellent surface passivation and an effective carrier transport is presented. High-efficiency n-type solar cells featuring this novel passivated rear contact instead of a point contact structure at the rear side yield a maximum efficiency of 23.7 %, a FF of 82.2 % and a Voc of 703 mV.