Mishra Leepsa, Kumar Ajay, Panigrahi Aradhana, Dubey Priyanka, Dutta Soumi, Parida Prakash, Sarangi Manas Kumar
Department of Physics, Indian Institute of Technology Patna, Bihar, India 801106.
J Phys Chem Lett. 2023 Aug 24;14(33):7340-7345. doi: 10.1021/acs.jpclett.3c01893. Epub 2023 Aug 10.
Optimization of perovskite-based optoelectronic performance demands prudent engineering in the device architecture with facile transport of generated charge carriers. Herein, we explore the charge transfer (CT) kinetics in perovskite nanocrystals (PNCs), CsPbBr, with two redox-active quinones, menadione (MD) and anthraquinone (AQ), and its alteration in halide exchanged CsPbCl. With a series of spectroscopic and microscopic measurements, we infer that both electron and hole transfer (ET-HT) prevail in CsPbCl with quinones, resulting in a faster CT, while ET predominates for CsPbBr. Furthermore, current-sensing atomic force microscopy measurements demonstrate that the conductance across a metal-PNC-metal nanojunction is improved in the presence of quinones. The contributions of ET and HT to current conduction across PNCs are well supported and validated by theoretical calculations of the density of states. These outcomes convey a new perspective on the relevance of ET and HT in the optimal current conduction and optoelectronic device engineering of perovskites.
基于钙钛矿的光电器件性能优化需要在器件结构上进行精心设计，以使产生的电荷载流子能够轻松传输。在此，我们研究了钙钛矿纳米晶体（PNCs）CsPbBr中与两种具有氧化还原活性的醌（甲萘醌（MD）和蒽醌（AQ））的电荷转移（CT）动力学，以及卤化物交换后的CsPbCl中的电荷转移动力学变化。通过一系列光谱和显微镜测量，我们推断在含有醌的CsPbCl中电子和空穴转移（ET-HT）都占主导，导致电荷转移更快，而在CsPbBr中电子转移占主导。此外，电流传感原子力显微镜测量表明，在醌存在的情况下，金属-PNC-金属纳米结的电导得到改善。态密度的理论计算很好地支持并验证了电子转移和空穴转移对通过PNCs的电流传导的贡献。这些结果为电子转移和空穴转移在钙钛矿最佳电流传导和光电器件工程中的相关性提供了新的视角。
