Recent advances in organic ternary solar cells

In recent years, ternary solar cells have become an important photovoltaic-technology since they combine the merits of both single junction and tandem solar cells with their processing ease, mechanical flexibility, and lightweight. To date, their efficiency has reached over 12%, which paved the way for commercialization of organic solar cells. In this review, we first present general principles of ternary solar cells, followed by a comprehensive review of recent advances in ternary systems including the D-1:D-2:A system and D:A(1): A(2) system. In the end, we summarize the fundamentals and provide a prospect on organic ternary solar cells.