2021 Adv. Energy Mater. (IF 29.368), 2D/3D Inorganic Perovskite Achieved over 20% PCE with Spontaneous Construction

　　Advanced Energy Materials (IF 29.368) published a research result in November 2021. The research team enhanced the hole extraction of inorganic perovskite solar cells through the spontaneous construction of multi-dimensional heterostructures and achieved an efficiency of more than 20%.

　　Because of excellent photoelectric performance, thermal stability and chemical stability, inorganic perovskite based on CsPbI_3−xBr_x has become a star of photovoltaic material. However, if you want to further improve the device performance, the significant energy loss caused by non-radiative recombination has become a major obstacle.

　　In this study, the research team developed a 2D/3D multidimensional structure that spontaneously formed at room temperature. The results showed that the Ruddlesden-Popper 2D (n = 1) perovskite formed on the top of CsPbI_3−xBr_x played a role in the following three aspects:

1. 1. mediating carrier transport
   2. maintaining a long-life charge separation state on the nanosecond time scale
   3. improving the efficiency of carrier current electron injection into the hole transport layer. And then, it improved the hole extraction efficiency and greatly reduced the serious interface non-radiative charge recombination.

Furthermore, the uncoordinated Pb²⁺ was effectively passivated, which significantly reduced the density of surface traps in the perovskite film and prolonged the charge lifetime.