Defect quantification in metal halide perovskites: The solid-state electrochemical alternative

2021 ◽  
Author(s):  
Michel De Keersmaecker ◽  
Neal R Armstrong ◽  
Erin L Ratcliff
Keyword(s):  
Solid State ◽  
Defect Density ◽  
Metal Halide ◽  
Electrochemical Methods ◽  
Semiconductor Materials ◽  
Halide Perovskites ◽  
Defect Quantification

Electrochemical methodologies are routinely used to determine energetics and defect density in semiconductor materials under operando conditions. For metal halide perovskites, electrochemical methods are restricted to a limited group of...

Colossal Barocaloric Effects with Ultralow Hysteresis in Two-Dimensional Metal–Halide Perovskites

2021 ◽  
Author(s):  
Jarad Mason ◽  
Jinyoung Seo ◽  
Ryan McGillicuddy ◽  
Adam Slavney ◽  
Selena Zhang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Phase Transitions ◽  
Solid State ◽  
Hydrostatic Pressure ◽  
Metal Halide ◽  
Two Dimensional ◽  
Vapor Compression ◽  
Entropy Changes ◽  
Halide Perovskites ◽  
Solid State Cooling

Abstract Nearly 4,400 TWh of electricity—20% of the total consumed in the world—is used each year by refrigerators, air conditioners, and heat pumps for cooling. In addition to the 2.3 Gt of carbon dioxide emitted during the generation of this electricity, the vapor-compression-based devices that provided the bulk of this cooling emitted fluorocarbon refrigerants with a global warming potential equivalent to 1.5 Gt of carbon dioxide into the atmosphere. With population and economic growth expected to dramatically increase over the next several decades, the development of alternative cooling technologies with improved efficiency and reduced emissions will be critical to meeting global cooling needs in a more sustainable fashion. Barocaloric materials, which undergo thermal changes in response to applied hydrostatic pressure, offer the potential for solid-state cooling with high energy efficiency and zero direct emissions, as well as faster start-up times, quieter operation, greater amenability to miniaturization, and better recyclability than conventional vapor-compression systems. Efficient barocaloric cooling requires materials that undergo reversible phase transitions with large entropy changes, high sensitivity to hydrostatic pressure, and minimal hysteresis, the combination of which has been challenging to achieve in existing barocaloric materials. Here, we report a new mechanism for achieving colossal barocaloric effects near ambient temperature that exploits the large volume and conformational entropy changes of hydrocarbon chain-melting transitions within two-dimensional metal–halide perovskites. Significantly, we show how the confined nature of these order–disorder phase transitions and the synthetic tunability of layered perovskites can be leveraged to reduce phase transition hysteresis through careful control over the inorganic–organic interface. The combination of ultralow hysteresis (< 1.5 K) and high barocaloric coefficients (> 20 K/kbar) leads to large reversible isothermal entropy changes (> 200 J/kg•K) at record-low pressures (< 300 bar). We anticipate that these results will help facilitate the development of barocaloric cooling technologies and further inspire new materials and mechanisms for efficient solid-state cooling.

Evaluation of the AMOEBA force field for simulating metal halide perovskites in the solid state and in solution

2020 ◽  
Vol 152 (2) ◽  
pp. 024117
Author(s):  
P. V. G. M. Rathnayake ◽  
Stefano Bernardi ◽  
Asaph Widmer-Cooper
Keyword(s):  
Solid State ◽  
Force Field ◽  
Metal Halide ◽  
Halide Perovskites ◽  
Amoeba Force Field

scholarly journals Interfaces in metal halide perovskites probed by solid-state NMR spectroscopy

2021 ◽  
Author(s):  
Clayton J. Dahlman ◽  
Dominik J. Kubicki ◽  
G. N. Manjunatha Reddy
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solar Energy ◽  
Energy Conversion ◽  
Solid State Nmr ◽  
Light Harvesting ◽  
Metal Halide ◽  
Single Junction ◽  
Halide Perovskites ◽  
Conversion Efficiencies

Metal halide perovskites (MHPs) are promising light harvesting and emitting materials that have enabled solar energy conversion efficiencies of over 25% in solution-processed single-junction cells, and found applications in flexible...

Molecularly imprinted nanocomposites of CsPbBr3 nanocrystals: An approach towards fast and selective gas sensor of explosive taggants

2022 ◽  
Author(s):  
Eduardo Aznar ◽  
Ivan Sanchez-Alarcon ◽  
ananthakumar soosaimanickam ◽  
Pedro Javier Rodríguez Cantó ◽  
Francisco Perez-Pla ◽  
...  
Keyword(s):  
Solid State ◽  
Gas Sensor ◽  
Chemical Sensors ◽  
Photophysical Properties ◽  
Metal Halide ◽  
Molecularly Imprinted ◽  
Halide Perovskites

Chemical sensors based on metal halide perovskites have recently attracted tremendous interest because of their excellent photophysical properties. In this work, we report the synthesis of a solid-state luminescent gas...

scholarly journals Broadly tunable metal halide perovskites for solid-state light-emission applications

2017 ◽  
Vol 20 (8) ◽  
pp. 413-424 ◽  
Author(s):  
Sampson Adjokatse ◽  
Hong-Hua Fang ◽  
Maria Antonietta Loi
Keyword(s):  
Solid State ◽  
Light Emission ◽  
Metal Halide ◽  
Halide Perovskites

scholarly journals Low-toxic metal halide perovskites: opportunities and future challenges

2017 ◽  
Vol 5 (23) ◽  
pp. 11436-11449 ◽  
Author(s):  
Hang Hu ◽  
Binghai Dong ◽  
Wei Zhang
Keyword(s):  
Power Conversion ◽  
Toxic Metal ◽  
Metal Halide ◽  
Semiconductor Materials ◽  
The Past ◽  
Future Challenges ◽  
Halide Perovskites ◽  
Optoelectronic Applications ◽  
Conversion Efficiencies ◽  
Lead Halide

Over the past few years, lead halide perovskites have emerged as a class of dominant semiconductor materials in the photovoltaic (PV) field with an unprecedented sharp enhancement of power conversion efficiencies (PCEs) up to 22.1%, as well as in other promising optoelectronic applications due to their extraordinary and unique properties.

Stable down-conversion white light-emitting devices based on highly luminescent copper halides synthesized at room temperature

2021 ◽  
Author(s):  
Lintao Wang ◽  
Zhuang zhuang Ma ◽  
Fei Zhang ◽  
Meng Wang ◽  
Xu Chen ◽  
...  
Keyword(s):  
Solid State ◽  
White Light ◽  
Room Temperature ◽  
Metal Halide ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Halide Perovskites ◽  
Commercial Applications ◽  
Copper Halides ◽  
Down Conversion

As a newly-emerging candidate for solid-state phosphors, metal-halide perovskites have attracted intensive attention in the field of white light-emitting devices (WLEDs) recently. However, their further commercial applications are severely hampered...

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

2019 ◽  
Author(s):  
Subhajit Bhattacharjee ◽  
Sonu Pratap Chaudhary ◽  
Sayan Bhattacharyya
Keyword(s):  
Charge Carrier ◽  
Wide Spectrum ◽  
Real Life ◽  
Metal Halide ◽  
Lead Free ◽  
Water Medium ◽  
Type I ◽  
Type Ii ◽  
Perovskite Layer ◽  
Halide Perovskites

<p>Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9 </sub>(X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag<sub>2</sub>S and perovskite/TiO<sub>2 </sub>composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag<sub>2</sub>S and TiO<sub>2</sub> coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>/Ag<sub>2</sub>S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications. </p>

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