Phase Transitions and Anion Exchange in All-Inorganic Halide Perovskites

• DOI: 10.1021/accountsmr.0c00009
• Publication Date: 2020-09-14T15:06:23Z
• Authors: Julian A. Steele; Minliang Lai; Ye Zhang; Zhenni Lin; Johan Hofkens; Maarten B. J. Roe...; Peidong Yang
• Keywords: Technology; SOLAR-CELLS; Science & Technology; EFFICIENCY; Chemistry, Multidisciplinary; Materials Science; Materials Science, Multidisciplinary; 01 natural sciences; 7. Clean energy; 0104 chemical sciences; Chemistry; NANOCRYSTALS; Affordable and Clean Energy; LEAD BROMIDE; Physical Sciences; CH3NH3PBI3; IODIDE; CL; THERMAL-EXPANSION; BR; CONDUCTIVITY

ConspectusA new generation of semiconducting materials based on metal halide perovskites has recently been launched into the scientific spotlight, exhibiting outstanding optoelectronic properties and providing promise for development efficient optical devices. As a vivid example, solar cells made from these have quickly reached conversion efficiencies exceeding 25%, now par with well-established technologies, like silicon. Their widespread success is due, in part, to unique ability retain high-quality performance while being easily solution-processed thin films. This feature what defines them as brand-new class materials, compete traditional semiconductors requiring higher processing costs, III–Vs or II–IVs. However, interesting photophysics come catch; their soft ionic lattice promotes complex thermal-induced phase transitions high capacity postsynthetic compositional changes, e.g., anion exchange. Such dynamic behavior ultimately understanding several important structure–property relationships ambiguous obstructed clear path toward commercialization due inherent instability.Our aim this Account highlight fundamental aspects that dictate stable crystal structure enable exchange, through lens thermodynamic preference formation energies. Taking all-inorganic CsPbI3-xBrx system suitable case study, we focus ways which its thermodynamically unstable perovskite can be maintained at room temperature elucidate restructuring pathways taken during destabilization. In addition, will discuss origin mechanisms exchange CsPbX3 (X = I, Br, Cl) perovskites, emphasis direct visualization using situ microspectroscopy arriving quantitative results. For notable features dealt Account, strain stabilization, nonperovskite pathway, diffusion, attempt rationalize state-of-the-art modeling techniques.It within spirit not only modify broad range existing but also regulate enhanced material functionality. controlling partial changes local replacement composition CsBX3 (B Pb, Sn X nanowires facilitate heterojunctions, abrupt change correlated transition properties. From combined perspective, appear highly systems, whereby structural modifications large impact underlying stability Thus, ranging mechanism kinetics destabilization take place, tuning energy landscape external stimuli. We anticipate perspective topics help deepen our knowledge nature provide stimulus required build research directions utilizing versatile