A5066850217- Perovskite Materials and Applications
- Solid-state spectroscopy and crystallography
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Conducting polymers and applications
- Microfluidic and Capillary Electrophoresis Applications
- Optical properties and cooling technologies in crystalline materials
- Organic Light-Emitting Diodes Research
- 3D Printing in Biomedical Research
- Advanced Sensor and Energy Harvesting Materials
- Microfluidic and Bio-sensing Technologies
- 2D Materials and Applications
- Innovative Microfluidic and Catalytic Techniques Innovation
- Neuroscience and Neural Engineering
- Advanced biosensing and bioanalysis techniques
- Advanced Photocatalysis Techniques
- Molecular Junctions and Nanostructures
- ZnO doping and properties
- Synthesis and Properties of Aromatic Compounds
- Gas Sensing Nanomaterials and Sensors
- Advanced Chemical Physics Studies
- Nanofabrication and Lithography Techniques
- Semiconductor Quantum Structures and Devices
- Advancements in Solid Oxide Fuel Cells
- Advanced X-ray and CT Imaging
National Renewable Energy Laboratory
2022-2024
Swift Solar (United States)
2023
University of Oklahoma
2023
University of Notre Dame
2017-2019
University of Szeged
2019
Massachusetts Institute of Technology
2000-2002
IIT@MIT
2000
Oak Ridge National Laboratory
1999
American Ceramic Society
1999
The development of highly stable and efficient wide-bandgap (WBG) perovskite solar cells (PSCs) based on bromine-iodine (Br-I) mixed-halide (with Br greater than 20%) is critical to create tandem cells. However, issues with Br-I phase segregation under cell operational conditions (such as light heat) limit the device voltage stability. This challenge often exacerbated by ready defect formation associated rapid crystallization Br-rich chemistry antisolvent processes. We combined a gentle...
The light-emitting diodes (LEDs) used in indoor testing of perovskite solar cells do not expose them to the levels ultraviolet (UV) radiation that they would receive actual outdoor use. We report degradation mechanisms p-i-n-structured under unfiltered sunlight and with LEDs. Weak chemical bonding between perovskites polymer hole-transporting materials (HTMs) transparent conducting oxides (TCOs) dominate accelerated A-site cation migration, rather than direct HTMs. An aromatic phosphonic...
Abstract Perovskite photovoltaics have been shown to recover, or heal, after radiation damage. Here, we deconvolve the effects of based on different energy loss mechanisms from incident protons which induce defects can promote efficiency recovery. We design a dual dose experiment first exposing devices low-energy efficient in creating atomic displacements. Devices are then irradiated with high-energy that interact differently. Correlated modeling, (with increased ionizing component)...
Controlled-release systems are common in a number of product areas, including foods, cosmetics, pesticides, and paper. Microencapsulated systems, for example, used the release flavors vitamins fragrances perfumes, inks carbonless copy drug delivery first appeared 1960s 1970s. In past three decades, variety controlled drug-delivery applications has increased dramatically. Many these use polymers having particular physical or chemical characteristics such as biodegradability, biocompatibility,...
The ease of halide ion exchange in metal nanocrystals offers an opportunity to utilize them a layered or tandem fashion achieve graded bandgap films. We have now successfully suppressed the by capping CsPbBr3 and CsPbI3 with PbSO4–oleate create nanostructure assembly that inhibits anions. Absorption measurements show nanocrystal assemblies maintain their identity as either for several days. Furthermore, effect on excited state dynamics has also been elucidated. effectiveness lead perovskite...
The unique optoelectronic properties of lead halide perovskites have triggered a new wave excitement in materials chemistry during the past five years. Electrochemistry, spectroelectrochemistry, and photoelectrochemistry could be viable tools both for analyzing features these assembling them into hybrid architectures (e.g., solar cells). At same time, instability limits pool solvents electrolytes that can employed such experiments. focus our study is to establish stability window...
MAPbBr3 and MAPbI3 films cast onto glass slides physically paired together undergo halide exchange to form mixed films. The change in composition these two ∼130 nm thick occurs concurrently with Br– diffusing toward the film I– film. diffusion of species, which is tracked through changes absorption, offers a direct measurement thermally activated perovskite increase rate constant increasing temperature (from 8.3 × 10–6 s–1 at 23 °C 3.7 10–4 140 °C) follows an Arrhenius relationship...
The suppression of halide ion exchange between CsPbBr3 and CsPbI3 nanocrystals achieved through capping with PbSO4–oleate has enabled us to deposit different perovskite as aligned arrays on the electrode surfaces without intermixing species. electrophoretic deposition PbSO4–oleate-capped CsPbX3 (X = Cl, Br, I) suspended in hexane solution mesoscopic TiO2 films allows design controlled architecture single or multiple layers films. hierarchy assembly these is seen first linearly organized...
The development of metal halide perovskite/perovskite heterostructures is hindered by rapid interfacial diffusion leading to mixed alloys rather than sharp interfaces. To circumvent this outcome, we developed an ion-blocking layer consisting single-layer graphene (SLG) deposited between the perovskite layers and demonstrated that it effectively blocks anion in a CsPbBr3/SLG/CsPbI3 heterostructure. Spatially resolved elemental analysis spectroscopic measurements demonstrate halides do not...
Record-breaking efficiency achieved with quantum dot solar cells made of perovskite nanocrystals demands understanding the excited-state interactions between and metal oxide electron transport layers. The interfacial transfer excited CsPbBr3 oxides (TiO2, SnO2, ZnO) was elucidated using transient absorption spectroscopy found to occur a rate constant in range 2–4 × 1010 s–1. In an inert atmosphere, back helps maintain stability nanocrystals. However, presence oxygen introduces instability as...
The charging of a mesoscopic TiO
The presence of unreacted lead iodide in organic–inorganic halide perovskite solar cells is widely correlated with an increase power conversion efficiency. We investigate the mechanism for this by identifying role surfaces and interfaces present between methylammonium films excess iodide. show how type I II band alignments arising under different conditions result either passivation surface defects or hole injection. Through first-principles simulations solid–solid interfaces, we find that...
The control of grain size and surface properties is an important parameter in controlling the optoelectronic photovoltaic metal halide perovskites. When CsPbBr3 nanocrystal (∼10 nm diameter) films were annealed at 100–125 °C, they grow to produce ∼400 diameter crystallites while transforming into bulk perovskite films. Characteristic changes optical noted when such transformation occurred from nanocrystals bulk. By tracking absorbance emission spectra morphological different annealing times...
Cesium lead halide perovskite films with a systematic change in the composition of CsPbBr3-xIx, which iodide concentration varies from x = 0 to 3, provide built-in gradient band structure. Such structure allows for integrated capture visible photons and directs them energetically low-lying rich region. Annealing at temperatures ranging 50 °C 90 causes homogenize into mixed perovskites. The movement ions during homogenization process was elucidated using UV-Visible absorbance X-ray...
Abstract The presence of hot carriers is presented in the operational properties an (FA,Cs)Pb(I, Br, Cl) 3 solar cell at ambient temperatures and under practical concentration. Albeit, a device architecture that not suitably designed as functional carrier cell. At 100 K, clear evidence observed both high energy tail photoluminescence spectra from appearance nonequilibrium photocurrent higher fluence light J–V measurements. room temperature, however, emission elevated laser shown to compete...
Owing to its high hole conductivity and ease of preparation, CuI was among the first inorganic hole-transporting materials that were introduced early on in metal halide perovskite solar cells, but full potential as a semiconductor material is still be realized. We have now performed ultrafast spectroelectrochemical experiments ITO/CuI electrodes show effect applied bias excited-state dynamics CuI. Under operating conditions, recombination excitons dependent bias, it can accelerated by...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTElectrodeposition of Hole-Transport Layer on Methylammonium Lead Iodide Film: A Strategy To Assemble Perovskite Solar CellsGergely F. SamuGergely SamuRadiation Laboratory, University Notre Dame, Indiana 46556, United StatesDepartment Physical Chemistry and Materials Science, Szeged, Rerrich Square 1, Szeged H-6720, HungaryELI-ALPS Research Institute, Dugonics 13, 6720, HungaryMore by Gergely Samu, Rebecca A. ScheidtRebecca ScheidtRadiation...
Surface ligands are often used to improve perovskite solar cells (PSCs). Here, a series of surface with varying dipole moments applied at the methylammonium lead iodide (MAPbI3)/C60 interface vary energy-level alignment. All investigated PSC performance, 4-fluorophenethylammonium (FPEAI) displaying greatest improvement. Transient absorption and reflectance measurements show similar recombination dynamics in all ligand-treated MAPbI3/C60 bilayer films. photovoltage also lifetimes...
The photovoltaic parameters of triple cation perovskite [Cs0.05FA0.79MA0.16Pb(I0.83Br0.17)3] solar cells are investigated focusing on the electro-optical properties and differences in performance at low high temperatures. signature a parasitic barrier to carrier extraction is observed temperatures, which results loss T < 200 K. Intensity-dependent measurements indicate across this interface limited by combination exciton binding energy thermionic emission. However, device recovered...
Controlled-release systems are common in a number of product areas, including foods, cosmetics, pesticides, and paper. Microencapsulated systems, for example, used the release flavors vitamins fragrances perfumes, inks carbonless copy drug delivery first appeared 1960s 1970s. In past three decades, variety controlled drug-delivery applications has increased dramatically. Many these use polymers having particular physical or chemical characteristics such as biodegradability, biocompatibility,...
A microchip has been designed for use as an implantable drug delivery device. Each dosage of is contained in individually addressable microreservoir. This device no moving parts, but instead relies on electrochemical reaction to remove the gold cap off a reservoir. After removed, active substance inside well free dissolve or diffuse into surrounding solution. The performance phosphate buffered saline and calf serum evaluated using release fluorescent dye. kinetics are slower than saline,...