Perovskite solar cells' performance is expected to improve

Recently, Nature Photonics published online the research results of Wuhan University, Hong Kong Polytechnic University and University of California, Los Angeles on perovskite solar cells with stable, low open-circuit voltage loss through multi-functional passivation.  This research method is expected to be extended to inverted, mesoscopic and even laminated perovskite photovoltaic devices, which will help to realize stable and low open-circuit voltage loss perovskite single or multiple solar cells, and provide a new idea for promoting the development of perovskite cells.

It is reported, organic - inorganic hybrid perovskite excellent photoelectric properties, perovskite certification photoelectric conversion efficiency of solar cell is more than 25%, is expected to more than the efficiency of monocrystalline silicon solar cells (26.7%), and further improve the efficiency and stability of the perovskite battery, also helps to accelerate the commercialization of the perovskite solar cells.  

Short-circuit current density (JSC), open-circuit voltage (VOC) and fill factor (FF) are three important parameters to determine the efficiency of perovskite cells.  The research of JSC and FF has made a breakthrough, and VOC loss has become an important factor limiting the efficiency of perovskite cells.  In general, non-radiative compound losses within and at the interface of perovskite films are considered to be the main factor limiting VOC in perovskite cells.  

In this study, butylamine molecules were used to treat the three-dimensional perovskite surface. On the one hand, a two-dimensional passivation layer with gradient energy level distribution was formed on the three-dimensional perovskite surface.  On the other hand, butylamine molecules diffused from top to bottom under the drive of thermodynamics, forming 2D / 3D bulk heterojunctions at grain boundaries within the perovskite film, thus effectively reducing the concentration of surface defects and volume defects in the 3D perovskite film.  The synergistic passivation strategy of surface and in vivo can effectively reduce the non-radiative composite loss in perovskite films with different bandgap widths.  At the same time, due to the good environmental stability of 2D perovskite, the stability of 2D / 3D perovskite batteries prepared by this method has been significantly improved.