Quantitative Phase-Change Thermodynamics and Metastability of Perovskite-Phase Cesium Lead Iodide.

Title Quantitative Phase-Change Thermodynamics and Metastability of Perovskite-Phase Cesium Lead Iodide.
Authors S. Dastidar; C.J. Hawley; A.D. Dillon; A.D. Gutierrez-Perez; J.E. Spanier; A.T. Fafarman
Journal J Phys Chem Lett
DOI 10.1021/acs.jpclett.7b00134
Abstract

The perovskite phase of cesium lead iodide (?-CsPbI3 or "black" phase) possesses favorable optoelectronic properties for photovoltaic applications. However, the stable phase at room temperature is a nonfunctional "yellow" phase (?-CsPbI3). Black-phase polycrystalline thin films are synthesized above 330 °C and rapidly quenched to room temperature, retaining their phase in a metastable state. Using differential scanning calorimetry, it is shown herein that the metastable state is maintained in the absence of moisture, up to a temperature of 100 °C, and a reversible phase-change enthalpy of 14.2 (±0.5) kJ/mol is observed. The presence of atmospheric moisture hastens the black-to-yellow conversion kinetics without significantly changing the enthalpy of the transition, indicating a catalytic effect, rather than a change in equilibrium due to water adduct formation. These results delineate the conditions for trapping the desired phase and highlight the significant magnitude of the entropic stabilization of this phase.

Citation S. Dastidar; C.J. Hawley; A.D. Dillon; A.D. Gutierrez-Perez; J.E. Spanier; A.T. Fafarman.Quantitative Phase-Change Thermodynamics and Metastability of Perovskite-Phase Cesium Lead Iodide.. J Phys Chem Lett. 2017;8(6):12781282. doi:10.1021/acs.jpclett.7b00134

Related Elements

Iodine

See more Iodine products. Iodine (atomic symbol: I, atomic number: 53) is a Block P, Group 17, Period 5 element with an atomic radius of 126.90447. The number of electrons in each of Iodine's shells is 2, 8, 18, 18, 7 and its electron configuration is [Kr] 4d10 5s2 5p5. The iodine atom has a radius of 140 pm and a Van der Waals radius of 198 pm. In its elemental form, iodine has a lustrous metallic gray appearance as a solid and a violet appearance as a gas or liquid solution. Elemental IodineIodine forms compounds with many elements, but is less active than the other halogens. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide. Iodine compounds are important in organic chemistry and very useful in the field of medicine. Iodine was discovered and first isolated by Bernard Courtois in 1811. The name Iodine is derived from the Greek word "iodes" meaning violet.

Cesium

See more Cesium products. Cesium (or Caesium) (atomic symbol: Ce, atomic number: 55) is a Block S, Group 1, Period 6 element with an atomic weight of 132.9054519. The number of electrons in each of Cesium's shells is 2, 8, 18, 18, 8, 1 and its electron configuration is [Xe]6s1. Cesium Bohr ModelThe cesium atom has a radius of 265 pm and a Van der Waals radius of 343 pm. Cesium is a member of the alkali group of metals. It is one of three metals that occur as a liquid at room temperature, the others being mercury and gallium. Elemental CesiumCesium's main commercial source is pollucite ore; however, it is also found in beryl, avogadrite, pezzottaite, and londonite. Cesium was discovered by Robert Bunsen and Gustav Kirchhoff in 1860 and first isolated by Carl Setterberg in 1882. In its elemental form, cesium has a silvery gold appearance. The word Cesium originates from the Latin word "caesius," meaning "sky blue," which refers to the vibrant blue lines in its spectrum.

Lead

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