Natural and engineered perovskites

 钙钛矿综述---自然界与工程应用中的钙钛矿

Perovskite is an unremarkable calcium titanium oxide mineral discovered in 1839 with an extremely versatile crystal structure. The compact crystal structure marks the transition to Earth's lower mantle as silicate perovskite becomes stable. Silicate perovskites make up the bulk of the lower mantle and are the most abundant minerals in Earth. The importance of perovskites extends to exoplanets, because silicate perovskites are stable in the mantle of planets larger than Mars.

钙钛矿（Perovskite）是一种不起眼的钙钛氧化物矿物，于1839年被发现，其晶体结构极其多样。随着硅酸盐钙钛矿变得稳定，它致密的晶体结构标志着其转化为地球的下地幔。硅酸盐钙钛矿是下地幔的主要组成成分，同时也是土壤中最丰富的矿物质。钙钛矿的重要性甚至可以延伸到太阳系外行星，因为硅酸盐钙钛矿在直径比火星大的行星地幔中是稳定的。

The perovskite crystal structure can accommodate a wide variety of cations, which allows the development of many materials. The cuprate high-temperature superconductors adopt a structure that can be described as an oxygen-deficient multilayered perovskite. Organic-inorganic hybrid perovskite solar cells have power conversion efficiencies exceeding 20%. Inorganic perovskite nanoparticles display bright, narrow-band photoluminescence that is useful in optoelectronics. Further development efforts will focus on improving material stability.

钙钛矿型晶体结构可搭配多种阳离子，从而可以演变出许多种矿物质。铜氧化物高温超导体的结构可以描述为缺氧的层状钙钛矿结构；有机无机杂化钙钛矿太阳能电池的光电转换效率超过20%；无机钙钛矿纳米颗粒可以发出明亮而光谱较窄的荧光，在电光领域具有不错的应用价值。未来的发展都集中在提高材料的稳定性上。

The tunability of the perovskite structure also makes these crystals attractive for catalysis and electrocatalysis. In solid oxide fuel cells, perovskites serve as oxygen ion conductors separating anodes and cathodes. For applications such as automotive pollution control, perovskite catalysts based on earth-abundant elements could provide alternatives to existing catalysts based on scarce precious metals.

钙钛矿结构的可调性也使得这些晶体在催化和电催化领域具有应用价值。在固体氧化物燃料电池，钙钛矿在作为氧离子导体的同时分离阳极和阴极。在汽车污染控制等应用领域，基于地球含量丰富的元素的钙钛矿催化剂有可能替代现有的贵重金属催化剂。

Methodological developments, including high-pressure diamond anvil cells and advanced spectroscopic techniques, help drive our understanding of perovskites. Experimental breakthroughs are complemented by theoretical approaches that can now tackle such complex structures. Continued progress will be spurred by societal needs and aided by synergy between the different subdisciplines that have investigated this fascinating mineral structure.

研究手段的发展，包括高压金刚石砧室和先进的光谱技术，有助于我们理解钙钛矿。实验方面的突破辅以理论研究手段，现在已可以很好的研究这种复杂的结构。后续的发展主要是看社会的需求和各类研究这个令人着迷的矿物结构的学科之间的协作。

文章来源: Science  10 Nov 2017 （Vol. 358, Issue 6364, pp. 732-733）

作者：Phillip Szuromi, Brent Grocholski

图片: L. PROTESESCU AND N. SCHWITZ