Perspective of a new trend in organic photovoltaic: ternary blend polymer solar cells

In the past few years, ternary polymer solar cells (PSCs) have emerged as a promising structure to simultaneously improve all solar cell parameters compared with traditional binary PSCs. The third component in ternary PSCs can play versatile functions to enhance the device performance. In this review, we summarize the design rules for fabricating high-performance ternary PSCs and introduce the recent progress in this field. In addition, the characterization methods for determining the role of the third component played in ternary PSCs are described.