Photoexcited Dynamics in Metal Halide Perovskites: From Relaxation Mechanisms to Applications

Abstract

The past decade has witnessed a growing interest in metal halide perovskite (MHP) materials, driven by their promising applications in photovoltaics and optoelectronics. The further pursuit of improved performance and stability will rely on a clear understanding of the fundamental properties of these materials. In this Feature Article, we outline a representative set of studies detailing how ultrafast laser spectroscopy can be used to access the optoelectronic properties and photophysical mechanisms of halide perovskites. Beginning with a concise synopsis of MHP history and structural properties, the dynamic processes in MHPs related to the photovoltaic performance are discussed. A brief overview of the representative time-resolved optical spectroscopic techniques in MHP research is then provided. Afterward, the recent advances in exploring the carrier, lattice, and spatially resolved dynamic processes in halide perovskite are summarized. The last section is devoted to a range of applications using halide perovskites. Finally, our conclusions and outlook for the field with some predictions for future opportunities round off this Feature Article.

Ultrafast Relaxation of Symmetry-Breaking Photo-Induced Atomic Forces

“…The interpolation of the electronic bandstructure of Bi, Sb and As are shown in Figs. 4, 5 and 6 respectively. These were performed using 14 Wan- nier orbitals for Bi and 16 Wannier orbitals for Sb and As.…”

“…The generation and control of atomic forces in optically excited molecules and materials is important for a number of areas including photocatalysis [1], laser annealing and the study of photo-assisted phase transitions [2,3], with applications that include the development of efficient renewable energy [4] and phase-change memories [5,6]. The development of ultrafast optical spectroscopy has greatly advanced our understanding of electron and phonon dynamics in optically excited materials, with time resolution on the tens-of-femtoseconds scale readily accessible [7].…”

Interfaces in metal halide perovskites probed by solid-state NMR spectroscopy

“…[280][281][282] Nonetheless, even non-ultrafast scattering integrates distinct 'snapshots' of atomic positions. The photocarriers formed aer initial scattering events migrate, scatter and recombine over timescales ranging from fs to ms. Photocarrier dynamics in MHPs have attracted a great deal of experimental and theoretical research, 279,[283][284][285][286] and impact optoelectronic device performance. Fast radiative recombination rates and strong exciton binding are benecial for lightemitting applications to prevent non-radiative recombination, 15 but longer lifetimes and diffusion distances aid in photogenerated charge extraction for photovoltaic devices.…”

All-Inorganic CsPbBr3 Nanocrystals: Gram-Scale Mechanochemical Synthesis and Selective Photocatalytic CO2 Reduction to Methane

“…7 However, further progress is needed to efficiently reduce CO 2 in gas photocatalytic reactors, tackling the limitations of most photocatalysts, namely poor light absorption, low CO 2 adsorption, poor separation and transfer of photoinduced charges, and poor selectivity for certain carbon-based products such as CH 4 or CO. 8 In recent years, due to their high extinction coefficients, visible-light absorption and long electron and hole diffusion lengths, halide perovskites have emerged as promising materials for optoelectronic applications, especially in photovoltaic devices with a current record power conversion efficiency above 25%. [9][10][11][12] These halide perovskite materials have also been investigated in the field of photocatalysis, including H 2 evolution and CO 2 reduction. For example, all-inorganic CsPbX 3 (X: halide) perovskites have proven to be successful for photocatalytic CO 2 reduction, especially CsPbBr 3 perovskite.…”

“…In recent years, due to their high extinction coefficients, visible-light absorption, and long electron and hole diffusion lengths, halide perovskites have emerged as promising materials for optoelectronic applications, especially in photovoltaic devices with a current record power conversion efficiency above 25%. − These halide perovskite materials have also been investigated in the field of photocatalysis, including H 2 evolution and CO 2 reduction. For example, all-inorganic CsPbX 3 (X: halide) perovskites have proven to be successful for photocatalytic CO 2 reduction, especially CsPbBr 3 perovskite.…”