Low-cost and high-efficiency perovskite light-emitting diodes

Important results from the project

1) Through carefully optimizing the device structures and the perovskite active layers, high-performance green perovskite LEDs with external quantum efficiency of 14.4% were achieved. 2) I started independent research and achieved productive publications including papers in high impact journals of Chemistry Society Reviews, Advanced Materials and Energy and Environment Science etc. I was promoted to assistant professor on Feb 2018. 3) I have established strong and long-term collaboration with Prof Henry Snaith’s group at University of Oxford.

Expected long term effects

1) We developed several different methods to fabricate uniform and perovskite films with high luminescence, which is the not only important for perovskite LEDs but also useful for the development of other perovskite optoelectronic devices. 2) We systemically investigated the perovskite film formation process on different metal oxide and organic interlayers and first demonstrated the positive effect of ZnO/perovskite on the perovskite crystallization, which provides new insights to further optimize the interfacial contacts for high-performance perovskite LEDs.

Approach and implementation

1) We start from the optimization of perovskite films and noticed the effect of film morphology and the defects are critical to achieve high-quality perovskite emitting layer. We developed nitrogen quenching method and introduced different additives to improve the optoelectronic properties of the obtained perovskite films. 2) We noticed that the device stability of perovskite LEDs is still a big issue. With the introduction of stable inorganic cation, the device stability can be improved, however, the ion migration of perovskite still limits the stability improvement.