Coherent Transfer of Lattice Entropy via Extreme Nonlinear Phononics in Metal Halide Perovskites

Journal Article · 25 June 2024 · PRX Energy

DOI: https://doi.org/10.1103/PRXEnergy.3.023009 · OSTI ID:2473531

Liu, Z. ; Shi, Y.; Jiang, T.; Luo, L. ; Huang, C.; Mootz, M. ; Song, Z.; Yan, Y.; Yao, Y. ; Zhao, J.; Wang, J.

Entropy transfer in metal halide perovskites, characterized by significant lattice anharmonicity and low stiffness, underlies the remarkable properties observed in their optoelectronic applications, ranging from solar cells to lasers. The conventional view of this transfer involves stochastic processes occurring within a thermal bath of phonons, where the lattice arrangement and energy flow from higher- to lower-frequency modes. Here, we unveil a comprehensive chronological sequence detailing a conceptually distinct coherent transfer of entropy in a prototypical perovskite ${\mathrm{CH}}_3$ ${\mathrm{NH}}_3$ ${\mathrm{Pbl}}_3$ . The terahertz periodic modulation imposes vibrational coherence into electronic states, leading to the emergence of mixed (vibronic) quantum beat between approximately 3 and 0.3 THz. We highlight a well-structured bidirectional time-frequency transfer of these diverse phonon modes, each developing at different times and transitioning from high to low frequencies from 3 to 0.3 THz, before reversing direction and ascending to around 0.8 THz. First-principles molecular dynamics simulations disentangle a complex web of coherent-phononic coupling pathways and identify the salient roles of the initial modes in shaping entropy evolution at later stages. Capitalizing on coherent entropy transfer and dynamic anharmonicity presents a compelling opportunity to exceed the fundamental thermodynamic (Shockley-Queisser) limit of photoconversion efficiency and to pioneer novel optoelectronic functionalities. Published by the American Physical Society 2024

• Research Organization: Ames Laboratory (AMES), Ames, IA (United States)
• Sponsoring Organization: US Air Force Office of Scientific Research (AFOSR); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 2473531
• Report Number(s): IS-J--11,370; 023009
• Journal Information: PRX Energy, Journal Name: PRX Energy Journal Issue: 2 Vol. 3; ISSN 2768-5608
• Publisher: American Physical SocietyCopyright Statement
• Country of Publication: United States
• Language: English