Perovskite | EPFL Graph Search

Perovskite (pronunciation: pə'rɒvskaɪt) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as (XIIA2+VIB4+X2−3), known as the perovskite structure. Many different cations can be embedded in this structure, allowing the development of diverse engineered materials. The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856). Perovskite's notable crystal structure was first described by Victor Goldschmidt in 1926 in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. Found in the Earth's mantle, perovskite's occurrence at Khibina Massif is restricted to the silica under-saturated ultramafic rocks and foidolites, due to the instability in a paragenesis with feldspar. Perovskite occurs as small anhedral to subhedral crystals filling interstices between the rock-forming silicates. Perovskite is found in contact carbonate skarns at Magnet Cove, Arkansas, in altered blocks of limestone ejected from Mount Vesuvius, in chlorite and talc schist in the Urals and Switzerland, and as an accessory mineral in alkaline and mafic igneous rocks, nepheline syenite, melilitite, kimberlites and rare carbonatites. Perovskite is a common mineral in the Ca-Al-rich inclusions found in some chondritic meteorites. The stability of perovskite in igneous rocks is limited by its reaction relation with sphene. In volcanic rocks perovskite and sphene are not found together, the only exception being an etindite from Cameroon. A rare-earth-bearing variety knopite with the chemical formula is found in alkali intrusive rocks in the Kola Peninsula and near Alnö, Sweden. A niobium-bearing variety dysanalyte occurs in carbonatite near Schelingen, Kaiserstuhl, Germany. In stars and brown dwarfs the formation of perovskite grains is responsible for the depletion of titanium oxide in the photosphere.

A thermotropic liquid crystal enables efficient and stable perovskite solar modules

Mohammad Khaja Nazeeruddin, Yong Ding, Bin Ding, Yi Yang, Cheng Liu, Jian Xu

Perovskite solar cells have seen impressive progress in performance and stability, yet maintaining efficiency while scaling area remains a challenge. Here we find that additives commonly used to passivate large-area perovskite films often co-precipitate du ...

Berlin2024

Mixed ionic-electronic conduction in Ruddlesden-Popper and Dion-Jacobson layered hybrid perovskites with aromatic organic spacers

Michael Graetzel, Jovana Milic, Joachim Maier, Algirdas Ducinskas, Yuchen Wang, Davide Moia, Mina Jung

The understanding of mixed ionic-electronic conductivity in hybrid perovskites has enabled major advances in the development of optoelectronic devices based on this class of materials. While recent investigations revealed the potential of using dimensional ...

Royal Soc Chemistry2024

Axial-Equatorial Halide Ordering in Layered Hybrid Perovskites from Isotropic-Anisotropic 207Pb NMR

David Lyndon Emsley, Michael Allan Hope, Ümmügülsüm Günes, Manuel Cordova, Aditya Mishra

Bandgap-tuneable mixed-halide 3D perovskites are of interest for multi-junction solar cells, but suffer from photoinduced spatial halide segregation. Mixed-halide 2D perovskites are more resistant to halide segregation and are promising coatings for 3D per ...

Weinheim2024