Perovskite (structure)

About: Perovskite (structure) is a research topic. Over the lifetime, 51482 publications have been published within this topic receiving 1541750 citations.

Ferroelectricity of CH3NH3PbI3 Perovskite

Abstract: Ferroelectricity has been believed to be an important but controversial origin of the excellent photovoltaic performance of organometal trihalide perovskites (OTPs). Here we investigate the ferroelectricity of a prototype OTP, CH3NH3PbI3 (MAPbI3), both theoretically and experimentally. Our first-principles calculations based on 3-D periodic boundary conditions reveal that a ferroelectric structure with polarization of ∼8 μC/cm2 is the globally stable one among all possible tetragonal structures; however, experimentally no room-temperature ferroelectricity is observed by using polarization–electric field hysteresis measurements and piezoresponse force microscopy. The discrepancy between our theoretical and experimental results is attributed to the dynamic orientational disorder of MA+ groups and the semiconducting nature of MAPbI3 at room temperature. Therefore, we conclude that MAPbI3 is not ferroelectric at room temperature; however, it is possible to induce and experimentally observe apparent ferroelect...

Effect of pressure, temperature, and composition on lattice parameters and density of (Fe,Mg)SiO3-perovskites to 30 GPa

Abstract: High-pressure, high-temperature properties of MgSiO3, (Fe01Mg09)SiO3, and (Fe02Mg08)SiO3 perovskites have been investigated using a newly developed X ray diffraction technique involving monochromatic synchrotron radiation The first direct measurements of unit cell distortions and equation-of-state parameters of the orthorhombic perovskite as functions of composition and simultaneous high pressure and high temperature were obtained The experiments were conducted under hydrostatic pressure up to 30 GPa, into the stability field of the perovskite The results demonstrate that the perovskite is elastically anisotropic, with the lattice parameter b being 25% less compressible than a and c Under increasing pressures the orthorhombic perovskite is distorted further away from the ideal cubic structure in agreement with theoretical predictions The 298-K isothermal equations of state of the three perovskites are indistinguishable within the uncertainty limits of the experiment The zero-pressure bulk modulus KT0 = 261 (±4) GPa with its pressure derivative KT0′ = 4 is close to that determined in previous static high pressure measurements The thermal expansion obtained from the high P - T experiments are consistent with previous measurements carried out at zero pressure but shows a strong volume dependence The temperature derivative of the isothermal bulk modulus at constant pressure (∂KT/∂T)p is −63(±05)×10−2 GPa/K Analyses of the high-temperature data give a value for the Anderson-Gruneisen parameter δT of 65–75, which is significantly higher than that used in recent lower mantle models

Tuning Molecular Interactions for Highly Reproducible and Efficient Formamidinium Perovskite Solar Cells via Adduct Approach

Abstract: The Lewis acid–base adduct approach has been widely used to form uniform perovskite films, which has provided a methodological base for the development of high-performance perovskite solar cells. However, its incompatibility with formamidinium (FA)-based perovskites has impeded further enhancement of photovoltaic performance and stability. Here, we report an efficient and reproducible method to fabricate highly uniform FAPbI3 films via the adduct approach. Replacement of the typical Lewis base dimethyl sulfoxide (DMSO) with N-methyl-2-pyrrolidone (NMP) enabled the formation of a stable intermediate adduct phase, which can be converted into a uniform and pinhole-free FAPbI3 film. Infrared and computational analyses revealed a stronger interaction between NMP with the FA cation than DMSO, which facilitates the formation of a stable FAI·PbI2·NMP adduct. On the basis of the molecular interactions with different Lewis bases, we proposed criteria for selecting the Lewis bases. Owed to the high film quality, per...

Highly efficient all-inorganic perovskite solar cells with suppressed non-radiative recombination by a Lewis base.

Abstract: All-inorganic perovskite solar cells (PVSCs) have drawn increasing attention because of their outstanding thermal stability. However, their performance is still inferior than the typical organic-inorganic counterparts, especially for the devices with p-i-n configuration. Herein, we successfully employ a Lewis base small molecule to passivate the inorganic perovskite film, and its derived PVSCs achieved a champion efficiency of 16.1% and a certificated efficiency of 15.6% with improved photostability, representing the most efficient inverted all-inorganic PVSCs to date. Our studies reveal that the nitrile (C-N) groups on the small molecule effectively reduce the trap density of the perovskite film and thus significantly suppresses the non-radiative recombination in the derived PVSC by passivating the Pb-exposed surface, resulting in an improved open-circuit voltage from 1.10 V to 1.16 V after passivation. This work provides an insight in the design of functional interlayers for improving efficiencies and stability of all-inorganic PVSCs. There has been a hot competition to optimize the device performance for all-inorganic perovskite solar cells. Here Wang et al. employ a Lewis base molecule to suppresses the non-radiative recombination in the inverted device and achieve a champion efficiency of 16.1%.