Pious Johnpaul K, Basavarajappa Manasa G, Muthu Chinnadurai, Krishna Nayana, Nishikubo Ryosuke, Saeki Akinori, Chakraborty Sudip, Vijayakumar Chakkooth
Photosciences and Photonics Section, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram 695 019, India.
Academy of Scientific and Innovative Research (AcSIR), CSIR-NIIST Campus, Ghaziabad 201 001, India.
J Phys Chem Lett. 2020 Aug 20;11(16):6757-6762. doi: 10.1021/acs.jpclett.0c01772. Epub 2020 Aug 6.
Bismuth-based perovskites are attracting intense scientific interest due to low toxicity and excellent moisture stability compared to lead-based analogues. However, high exciton binding energy, poor charge carrier separation, and transport efficiencies lower their optoelectronic performances. To address these issues, we have integrated an electronically active organic cation, naphthalimide ethylammonium, between the [BiI] chains via crystal engineering to form a novel perovskite-like material (naphthalimide ethylammonium)BiI (NBI). Single crystal analysis revealed a one-dimensional quantum-well structure for NBI in which inter-inorganic well electronic coupling is screened by organic layers. It exhibited anisotropic photoconductivity and long-lived charge carriers with milliseconds lifetime, which is higher than that of CHNHPbI. Density functional theory calculations confirmed type-IIa band alignment between organic cations and inorganic chains, allowing the former to electronically contribute to the overall charge transport properties of the material.
与铅基类似物相比，铋基钙钛矿因其低毒性和出色的水分稳定性而引起了科学界的浓厚兴趣。然而，高激子结合能、较差的电荷载流子分离以及传输效率降低了它们的光电性能。为了解决这些问题，我们通过晶体工程在[BiI]链之间整合了一种具有电子活性的有机阳离子——萘二甲酰亚胺乙铵，以形成一种新型的类钙钛矿材料（萘二甲酰亚胺乙铵）BiI（NBI）。单晶分析揭示了NBI的一维量子阱结构，其中无机阱间的电子耦合被有机层屏蔽。它表现出各向异性的光电导性和具有毫秒级寿命的长寿命电荷载流子，这比CHNHPbI的寿命要长。密度泛函理论计算证实了有机阳离子与无机链之间的IIa型能带排列，使得前者能够对材料的整体电荷传输性质做出电子贡献。
