A5032755495- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Conducting polymers and applications
- 2D Materials and Applications
- Organic Light-Emitting Diodes Research
- Gas Sensing Nanomaterials and Sensors
- Transition Metal Oxide Nanomaterials
- Organic Electronics and Photovoltaics
- Optical properties and cooling technologies in crystalline materials
- Chalcogenide Semiconductor Thin Films
- Luminescence and Fluorescent Materials
- Random lasers and scattering media
- Supercapacitor Materials and Fabrication
- Crystallography and molecular interactions
- Fiber-reinforced polymer composites
- Advanced ceramic materials synthesis
- Analytical Chemistry and Sensors
- Graphene research and applications
- Coral and Marine Ecosystems Studies
- Porphyrin and Phthalocyanine Chemistry
- Catalytic Processes in Materials Science
- Luminescence Properties of Advanced Materials
- Semiconductor materials and devices
Lawrence Berkeley National Laboratory
2023-2024
Purdue University West Lafayette
2018-2023
University of Colorado Boulder
2017
Abstract Electroluminescence efficiencies and stabilities of quasi-two-dimensional halide perovskites are restricted by the formation multiple-quantum-well structures with broad uncontrollable phase distributions. Here, we report a ligand design strategy to substantially suppress diffusion-limited disproportionation, thereby enabling better control. We demonstrate that extending π-conjugation length increasing cross-sectional area enables perovskite thin films dramatically suppressed ion...
Abstract Surface passivation is an effective way to boost the efficiency and stability of perovskite solar cells (PSCs). However, a key challenge faced by most strategies reducing interface charge recombination without imposing energy barriers extraction. Here, novel multifunctional semiconducting organic ammonium cationic modifier inserted between light‐harvesting film hole‐transporting layer reported. It shown that conjugated cations can directly extract holes from efficiently,...
Quasi-2D halide perovskites have attracted much interest as a promising material for light-emitting diodes (LEDs) due to their tunability in quantum confinement and alloy formation modulate the energy bandgap emission color. However, two-factor phase separations with respect heterogeneous quantum-well thicknesses segregation are still crucial issues quasi-2D perovskite LEDs, leading low external efficiencies (EQEs) color shifts. Herein, we compare films using different cations unveil key...
Abstract Quasi‐2D hybrid halide perovskites have drawn considerable attention due to their improved stability and facile tunability compared 3D perovskites. The expansiveness of possibilities has thus far been limited by the difficulty in incorporating large ligands into thin‐film devices. Here, a bulky bi‐thiophene 2T ligand is focused on develop solvent system around creating strongly vertically‐aligned (2T) 2 (MA) 6 Pb 7 I 22 ( n = 7) quasi‐2D perovskite films. By starting with poorly...
Abstract The power conversion efficiency of organic solar cells (OSCs) is exceeding 20%, an advance in which morphology optimization has played a significant role. It generally accepted that the processing solvent (or mixture) can help optimize morphology, impacting OSC efficiency. Here we develop OSCs show strong tolerance to range solvents, with all devices delivering high efficiencies around 19%. By investigating solution states, film formation dynamics and characteristics processed films...
Abstract Metal halide perovskites have witnessed great success in green, red, and near‐infrared light‐emitting diodes (LEDs), yet blue LEDs still lag behind. Reducing undesired energetic disorders – broad n ‐phases segregation is considered as the most critical strategy to further improve performances. Here, study reports a newly designed synthesized di‐ammonium ligand with rigid π ‐conjugated rings additional methyl groups construct Dion–Jacobson (DJ) structure. Augmented coordination from...
Carbon superstructures are widely applied in energy and environment-related areas. Among them, the flower-like polyacrylonitrile (PAN)-derived carbon materials have shown great promise due to their high surface area, large pore volume, improved mass transport. In this work, we report a versatile straightforward method for synthesizing one-dimensional (1D) nanostructured fibers two-dimensional (2D) thin films based on PAN chemistry by taking advantage of nucleation growth behavior PAN. The...
Controlling the crystallization of perovskites is imperative to reduce defect densities in perovskite thin films and extend device lifetimes. In this work, combinations amine chalcogenide ligands were introduced sequential deposition method fabricate highly crystalline oriented formamidinium lead iodide with reduced increased charge carrier The dual additives can tune intermediate state control crystallization, leading devices improved efficiencies stabilities. While thiophenol failed...
Photoinduced interfacial charge transfer plays a critical role in energy conversion involving van der Waals (vdW) heterostructures constructed of inorganic nanostructures and organic materials. However, the effect molecular stacking configurations on dynamics is less understood. In this study, we demonstrated tunability separation type-II heterojunction between monolayer (ML) WS2 an semiconducting molecule [2-(3″′,4′-dimethyl-[2,2′:5′,2′:5″,2″′-quaterthiophen]-5-yl)ethan-1-ammonium halide...
Aromatic organic molecules are widely used as passivators in perovskite solar cells (PSCs). Efforts have been devoted to improving the energy alignments, band edge states, and defect passivation functionalities. However, potential loss through triplet states such conjugated has not investigated past. Here, we report observation of charge transfer from FAPbI3 state a pyrene (Pyr)-based cationic ligand. Such channel can be suppressed via delicate management polycyclic aromatic compounds....
Abstract Oxidation resistant, thin, pinhole‐free, crystalline mullite coatings were deposited on zirconia and silicon carbide particles using atomic layer deposition ( ALD ). The composition of the films was confirmed with inductively coupled plasma optical emission spectroscopy ICP OES ), conformality elemental dispersion characterized transmission electron microscopy TEM ) energy dispersive X‐ray EDS respectively. are particle surface a rate ~1 Å/cycle. concentration aluminum relative to...
Abstract Two‐dimensional (2D) organic‐inorganic hybrid materials are currently of great interest for applications in electronics and optoelectronics. Here, the synthesis optical properties a new type halide‐organothiolate‐mixed 2D material, Pb 2 X(S‐C 6 H 5 ) 3 , reported, which X is halide (I, Br, or Cl). Different from conventional lead‐based layered materials, these compounds feature unusual five‐coordinated lead centers with stereochemically active electron lone pair on atoms...
Abstract Metal halide perovskites show promise for next-generation light-emitting diodes, particularly in the near-infrared range, where they outperform organic and quantum-dot counterparts. However, still fall short of costly III-V semiconductor devices, which achieve external quantum efficiencies above 30% with high brightness. Among several factors, controlling grain growth nanoscale morphology is crucial further enhancing device performance. This study presents a engineering methodology...
Abstract Despite the outstanding electric properties and cost‐effectiveness of poly(3,4‐ethylenedioxythiophene) (PEDOT) its derivatives, their performance as hole transport layer (HTL) materials in conventional perovskite solar cells (PSCs) has lagged behind that widely used spirobifluorene‐based molecules or poly(triaryl amine). This gap is mainly from poor solubility energy alignment mismatch. In this work, design synthesis a pyrrole‐modified HTL (PPr) based on 3,4‐propylenedioxythiophene...
We present herein a custom-made, in situ, multimodal spin coater system with an integrated heating stage that can be programmed spinning and recipes is coupled synchrotron-based, grazing-incidence wide- small-angle x-ray scattering. The coating features adaptable experimental chamber, the ability to house multiple ancillary probes such as photoluminescence visible optical cameras, allow for true characterization correlated data analysis. This enables monitoring of structural evolutions...