(Invited) Realizing the Lowest Bandgap and Exciton Binding Energy in a Two-Dimensional Lead Halide System

Abstract

3-dimensional hybrid halide perovskites have been intensely researched because of their extraordinary optoelectronic properties with spectacular quantum efficiencies arising primarily from their suitable bandgaps to harvest the solar spectrum, low excitonic binding energies, and low-cost synthetic processes. However, stabilizing these materials under real-life operating conditions has proven to be a challenge, leading to extensive explorations of lower dimensional analogous hybrid halide materials that are often more stable, though generally having considerably higher bandgaps and excitonic binding energies. I shall present some of our investigations leading to the synthesis of a highly moisture-stable 2-dimensional hybrid lead halide material with the lowest bandgap and exciton binding energy within this class of compounds.1 I shall detail the origin of such a low bandgap and exciton binding energy, identifying the most critical control parameters to determine these properties. In addition, I shall also present preliminary results to suggest the beneficial impacts of incorporating the same organic ligand while making a solar photovoltaic device based on three-dimensional hybrid lead halide perovskites.Reference: Debasmita Pariari, Sakshi Mehta, Sayak Mandal, Arup Mahata, Titas Pramanik, Sujit Kamilya, Arya Vidhan, Tayur N. Guru Row, Pralay K. Santra, Shaibal K. Sarkar, Filippo De Angelis, Abhishake Mondal, and D. D. Sarma, Realizing the Lowest Bandgap and Exciton Binding Energy in a Two-Dimensional Lead Halide System, J. Am. Chem. Soc. 145, 15896 (2023).