A5020176954- Perovskite Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- ZnO doping and properties
- Organic Electronics and Photovoltaics
- Solid-state spectroscopy and crystallography
- Thin-Film Transistor Technologies
- Semiconductor Quantum Structures and Devices
- Organic Light-Emitting Diodes Research
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Ga2O3 and related materials
- Quantum and electron transport phenomena
- Gas Sensing Nanomaterials and Sensors
- Copper-based nanomaterials and applications
- Magnetic properties of thin films
- Nanowire Synthesis and Applications
- Advancements in Solid Oxide Fuel Cells
- Semiconductor materials and interfaces
- Molecular Junctions and Nanostructures
- 2D Materials and Applications
- Semiconductor Lasers and Optical Devices
National Renewable Energy Laboratory
2016-2025
University of Colorado Boulder
2018-2025
University of Colorado System
2022-2024
Arizona State University
2024
Colorado School of Mines
2021-2023
Monash University
2023
Sungkyunkwan University
2023
CY Cergy Paris Université
2023
Applied Physical Sciences (United States)
2023
University of Oxford
2023
Goldschmidt tolerance factor (t) is an empirical index for predicting stable crystal structures of perovskite materials. A t value between 0.8 and 1.0 favorable cubic structure, larger (>1) or smaller (<0.8) values usually result in nonperovskite structures. CH(NH2)2PbI3 (FAPbI3) can exist the α-phase (black phase) with good photovoltaic properties. However, it has a large more hexagonal δH-phase (yellow phase), δH-to-α phase-transition temperature higher than room temperature. On other...
Abstract Improving the long-term stability of perovskite solar cells is critical to deployment this technology. Despite great emphasis laid on stability-related investigations, publications lack consistency in experimental procedures and parameters reported. It therefore challenging reproduce compare results thereby develop a deep understanding degradation mechanisms. Here, we report consensus between researchers field for testing cell stability, which are based International Summit Organic...
Efficient all-perovskite tandem cells Organic-inorganic perovskite films can boost the output of conventional silicon solar in geometries by utilizing more light at blue end spectrum. Tandem that use only have been less successful because lack a suitable material with low bandgap replace silicon. Tong et al. report mixed tin-lead organic-inorganic containing small fraction guanidinium thiocyanate has bandgap, long charge-carrier lifetime, and efficiencies around 25%. Science , this issue p. 475
Tuning band gaps with three halides Tandem solar cells can boost cell efficiency by using two active layers to absorb the spectrum more completely, provided that are current-matched. Inorganic-organic perovskites tuned appropriate wide gap (∼1.7 electron volts) as top contained iodine and bromine or chlorine have short carrier diffusion lengths undergo photo-induced phase segregation. Xu et al. now report a method for incorporating chloride allows fabrication of stable triple-halide 1.67...
Photovoltaic applications of perovskite semiconductor material systems have generated considerable interest in part because predictions that primary defect energy levels reside outside the bandgap. We present experimental evidence this enabling property is halide-lead perovskite, CH3NH3PbI3 (MAPbI3), consistent with theoretical predictions. By performing X-ray photoemission spectroscopy, we induce and track dynamic chemical electronic transformations perovskite. These data show compositional...
Extrinsic ions (<italic>e.g.</italic>, Li<sup>+</sup>) migrate across perovskite solar cells and modify the TiO<sub>2</sub> layer, affecting device performance hysteresis.
Recent achievements of 2D perovskites for various optoelectronic applications along with their basic properties and future opportunities are discussed.
Spin injection sans magnetism Light-emitting diodes (LEDs) that emit circularly polarized light (spin-LEDs) have potential applications in three-dimensional displays, bioencoding, and tomography. The requisite spin polarization of the charge carriers is usually achieved with ferromagnetic contacts applied magnetic fields, but Kim et al. report on a room-temperature spin-LED relies instead chiral-induced selectivity organic layer. This layer selectively injected spin-polarized holes into...
Engineering perovskites with anions The bandgap of the perovskite top layer in tandem silicon solar cells must be tuned to ∼1.7 electron volts. Usually, cation composition is varied because bromine-rich anion compositions wide bandgaps are structurally unstable. Kim et al. show that by using phenethylammonium as a two-dimensional additive, along iodine and thiocyanate, films can stabilized. A cell delivered >26% certified power conversion efficiency, device maintained 80% its initial...
Abstract Organometallic halide perovskite solar cells (PSCs) have shown great promise as a low-cost, high-efficiency photovoltaic technology. Structural and electro-optical properties of the absorber layer are most critical to device operation characteristics. Here we present facile fabrication PSCs based on compact, large-grain, pinhole-free CH 3 NH PbI 3−x Br x (MAPbI 3− ) thin films with high reproducibility. A simple methylammonium bromide (MABr) treatment via spin-coating proper MABr...
The conclusions reached by a diverse group of scientists who attended an intense 2-day workshop on hybrid organic-inorganic perovskites are presented, including their thoughts the most burning fundamental and practical questions regarding this unique class materials, suggestions various approaches to resolve these issues.
Chiral molecules in Pb-halide 2D-layered films achieve up to 86% spin-polarized transport, enabling novel spintronic applications.
Abstract Over the past decade, global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven large part by improvements solar cell and module efficiencies, reduction manufacturing costs realization of levelized electricity that are now generally less than other energy sources approaching similar with storage included. Given this success, it is a particularly fitting time to assess state photovoltaics field technology...
The characterization and implementation of solution-processed, wide bandgap nickel oxide (NiOx) hole-selective interlayer materials used in bulk-heterojunction (BHJ) organic photovoltaics (OPVs) are discussed. surface electrical properties charge selectivity these thin films strongly dependent upon the chemistry, band edge energies, midgap state concentrations, as dictated by ambient conditions film pretreatments. Surface states were correlated with standards for oxide, hydroxide,...
Abstract Metal halide perovskite solar cells (PSCs) have risen in efficiency from just 3.81% 2009 to over 25.2% today. While metal perovskites excelled efficiency, advances stability are significantly more complex and progressed slowly. The advance of which is readily measured, stability, can require literally thousands hours demonstrate, be expected given the rapid rate innovation field. In face changing absorber composition, synthetic approaches, device stack components it necessary...
The ability to manipulate quantum dot (QD) surfaces is foundational their technological deployment. Surface manipulation of metal halide perovskite (MHP) QDs has proven particularly challenging in comparison that more established inorganic materials due dynamic surface species and low material formation energy; most conventional methods chemical targeted at the MHP QD will result transformation or dissolution crystal. In previous work, we have demonstrated record-efficiency solar cells...
The performance of three-dimensional (3D) organic-inorganic halide perovskite solar cells (PSCs) can be enhanced through surface treatment with 2D layered perovskites that have efficient charge transport. We maximized hole transport across the layers a metastable Dion-Jacobson (DJ) tuned orientational arrangements asymmetric bulky organic molecules. reduced energy barrier for increased out-of-plane rates by factor 4 to 5, and power conversion efficiency (PCE) PSC was 4.9%. With DJ layer, PCE...
Organic–inorganic halide perovskites incorporating two-dimensional (2D) structures have shown promise for enhancing the stability of perovskite solar cells (PSCs). However, bulky spacer cations often limit charge transport. Here, we report on a simple approach based molecular design organic to improve transport properties 2D perovskites, and use phenethylammonium (PEA) as an example. We demonstrate that by fluorine substitution para position in PEA form 4-fluorophenethylammonium (F-PEA),...