Science News: 2021 Nature Communications PCE 21.4% Active Area of 26cm2 Perovskite Module Set a Record!
Nature Communications (IF 14.919) published a study in November 2021. As a leader in emerging photovoltaic technologies, perovskite solar cells (PSCs) with certified power conversion efficiency (PCE) over 25% show great possibilities for scale-up and future commercialization due to relatively simple and low-cost. However, in solution-processed perovskite films (especially on the surfaces and grain boundaries), there is a problem of generating a large number of defects, so organic halide salt passivation is considered an important strategy to reduce defects. However, with this strategy, it is still difficult to avoid the formation of in-plane favored two-dimensional (2D) perovskite layer, causing damage to charge transfer. Under thermal conditions, it will hinder photovoltaic performance and device scale-up. In order to overcome this limitation, the authors studied the energy barrier of 2D perovskite, which is composed of ortho-, meta- and para-isomers of (phenylene) di (ethylammonium) iodide (PDEAI2) that were designed for tailored defect passivation.
Structures of PDEAI2 and subsequent formation of 2D perovskites.
The research team used a solar simulator to analyze its photovoltaic characteristics and used other instruments to assist in the experiments. It was found that treatment with the most sterically hindered ortho-isomer can prevent the formation of a 2D perovskite film on the surface regardless of high temperature and can maximize the passivation effect on both shallow- and deep-level defects. Use o-PDEAI2 (ortho-(phenylene) di (ethylammonium) iodide) passivation to increase the efficiency of PSC to 23.9% and ensure long term stability over 1000 h. More importantly, the perovskite module with an active area of 26cm2 reached a record efficiency of 21.4%. This study shows that altering the functional groups and chemical structure should be an effective strategy for the development of novel organic cationic passivators, and also pave the way for scaling up commercial applications in the future.
Passivation layer-dependent device performance.
Module performance and long-term stability of the PSCs. (c) J–V characteristics of the champion perovskite solar module with an active area of 26.00 cm2. (g) Maximum power point tracking (MPPT) for 1100 h of the unencapsulated devices under continuous light (100mWcm−2) illumination at 25 °C in a nitrogen atmosphere.