Self-deposited passivation for decreasing scalable processing loss of perovskite solar cells

Abstract

With the area of perovskite films and devices increases, the performance tends to deteriorate, which can be attributed to the accumulation of defects at the bottom surface without proper passivation. Here, we introduce the 1-(4-Fluorophenyl)−2-pyrrolidone molecule (FPP) as additive in large-area blade-coating perovskite films. During the top-down crystallization process, the FPP molecule form an intermediate phase with the perovskite components and subsequently self-deposit at the bottom surface. Consequently, the crystallization kinetics of the large-area thin films are regulated, and the bottom surface is effectively and uniformly passivated in one single-step processing. By employing this self-deposited passivation method (SDP), the efficiency decrease caused by the expansion of the device area has been significantly suppressed and the devices yield power conversion efficiency of 23.41% (0.09 cm2), 22.43% (1 cm2), and 20.75% (24 cm2). The method is compatible for commercial manufacturing with scaling up solar cell area and holding high efficiency. Blade-coating produces large-area perovskite solar cells, but device performance is often reduced as the area of the film increases. Here, an additive is used to control film crystallization to achieve high power conversion efficiency, attributed to a self-deposited passivation method