Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV24)
DOI: https://doi.org/10.29363/nanoge.hopv.2024.142
Publication date: 6th February 2024
In recent years, organic-inorganic hybrid perovskite solar cells have been attracting considerable attention due to their low cost and facile fabrication [1]. Since 2009 power conversion efficiency of perovskite solar cells devices has increased dramatically and currently exceeds 25% [2]. Although perovskite solar cells have achieved high efficiency, there are still several challenges limiting their commercialization. One of them is long-term stability. Under-coordinated defects are ubiquitous in hybrid organic-inorganic perovskite materials [3]. Such defects cause the electronic states of the perovskite to become discrete and form trap states within the band gap, which trap the free carriers to reduce the performance of perovskite solar cells, and particularly impact on larger-scale modules. To overcome the drawbacks, organic compounds with two N-carbazolyl based chromophores linked by aliphatic chains via two-step synthesis have been developed to merge the electronic states between defective and perfect perovskite sites. When the mentioned organic compounds were used in perovskite solar cells, it results in an improved fill factor (FF) of 84% and stability of 99.6% over 1000 h operation. Furthermore, the power conversion efficiency of a small cell reached 23.22%, and for a mini-module (6.5×7 cm2, active area = 30.24 cm2) 21.71% was obtained. This work shows that merging the trap states to a continuous electronic state reduces defect induced recombination and is an effective way to improve the performance of perovskite solar cells.