Hybrid-DFT study of halide perovskites, an energy-efficient material under compressive pressure for piezoelectric applications
L. Celestine, R. Zosiamliana, Lalrin Kima, B. Chettri, Y. T. Singh, Shivraj Gurung, Ningthoujam Surajkumar Singh, A. Laref, P. Raics
Abstract
Abstract Recent studies have reported that lead-halide perovskites are the most efficient energy-harvesting materials. Regardless of their high-output energy and structural stability, lead-based products have risk factors due to their toxicity. Therefore, lead-free perovskites that offer green energy are the expected alternatives. We have taken CsGeX 3 (X = Cl, Br, and I) as lead-free halide perovskites despite knowing the low power conversion rate. Herein, we have tried to study the mechanisms of enhancement of energy-harvesting capabilities involving an interplay between structure and electronic properties. A density functional theory simulation of these materials shows a decrease in the band gaps, lattice parameters, and volumes with increasing applied pressure. We report the high piezoelectric responses and high electro-mechanical conversion rates, which are intriguing for generating electricity through mechanical stress.