Dielectric Properties of Acetamidinium Substituted Methylammonium Lead Iodide Perovskite

Bhardwaj, S and Mohanty, A and Das, R and Singh, P and Singh, A and Sarma, DD and Avasthi, S (2022) Dielectric Properties of Acetamidinium Substituted Methylammonium Lead Iodide Perovskite. In: 2022 IEEE International Conference on Emerging Electronics, 11- 14 Dec 2022, Bangalore.

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Abstract

We study the dielectric properties of Acetamidinium lead iodide and ten percent Acetamidinium substituted Methylammonium lead iodide with pristine Methylammonium lead iodide, to understand the reason for the superior device performance of ten percent Acetamidinium substituted Methylammonium lead iodide. Measurements across a range of temperatures show that the dielectric constant in Acetamidinium lead iodide is significantly lower than Methylammonium lead iodide. One of the important findings of this report is a change in the pattern of curie-like behavior in the case of ten percent Acetamidinium substituted Methylammonium lead iodide when compared with zero percent substitution. In the case of zero percent substitution, the fall in dielectric constant after one hundred fifty kelvin is very steep, however, this curie temperature lowered to one hundred thirty eight kelvin with a slightly wider fall in the case of ten percent Acetamidinium substituted Methylammonium lead iodide due to restricted dipolar rotation of bulkier acetamidinium ion in the perovskite matrix. The fall in dielectric constant becomes even wider in pristine Acetamidinium lead iodide. So smaller exciton binding energy is not the reason for the improved performance of the mixed-cation lead iodide perovskite. It is the restricted rotation and bulkiness of Acetamidinium cation along with more H-bond that prevent the ion migration by increasing the activation energy of vacancy-mediated halide migration, which reduces interface recombination losses and improves device performance. © 2022 IEEE.

Item Type:	Conference Paper
Publication:	2022 IEEE International Conference on Emerging Electronics, ICEE 2022
Publisher:	Institute of Electrical and Electronics Engineers Inc.
Additional Information:	The copyright for this article belongs to Cation Substitution; Defects; Dielectric Constant; Hard Matrix; Interfaces; Ion Migration; Perovskite; Polarization; Soft Material
Keywords:	Cation Substitution; Defects; Dielectric Constant; Hard Matrix; Interfaces; Ion Migration; Perovskite; Polarization; Soft Material
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	28 Jun 2023 05:19
Last Modified:	28 Jun 2023 05:19
URI:	https://eprints.iisc.ac.in/id/eprint/82187

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