A5088365049- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- 2D Materials and Applications
- Solid-state spectroscopy and crystallography
- Conducting polymers and applications
- Chalcogenide Semiconductor Thin Films
- Water Quality Monitoring and Analysis
- Semiconductor Lasers and Optical Devices
- ZnO doping and properties
- Neural Networks and Applications
- Ga2O3 and related materials
- Transition Metal Oxide Nanomaterials
- Semiconductor Quantum Structures and Devices
- Machine Learning in Materials Science
- Advanced Semiconductor Detectors and Materials
Brigham Young University
2020-2024
University of Chicago
2024
National Renewable Energy Laboratory
2023
Abstract Aside from band gap reduction, little is understood about the effect of tin‐for‐lead substitution on fundamental optical and optoelectronic properties metal halide perovskites (MHPs), especially when transitioning 3D to lower dimensional structures. Herein, we take advantage spectroscopic isolation excitons in 2D MHPs study intrinsic differences between lead tin MHPs. The exciton's spectral fine structure indicates a larger polaron binding energy Additionally, electroabsorption...
Because of the vital role temperature in many biological processes studied microfluidic devices, there is a need to develop improved sensors and data analysis algorithms. The photoluminescence (PL) nanocrystals (quantum dots) has been successfully used but accuracy reconstructed limited about 1 K over range tens degrees. A machine learning algorithm consisting fully connected network seven layers with decreasing numbers nodes was developed applied combination normalized spectral...
The established theory of a two-dimensional (2D) Wannier exciton in uniform electric field is used to analyze the electroabsorption response an archetypal 2D metal halide perovskite (MHP), phenethylammonium lead iodide. high level agreement between simulation and measurement allows for deepened understanding redshift energy, according quadratic Stark effect, continuum wave function leaking, Franz-Keldysh effect. We find dependency each these effects be rich with information, yielding...
The coupling between the polar lattice and electronic system is a key ingredient enabling impressive properties of 2D 3D metal-halide perovskites (MHPs). For example, mechanisms such as polaron formation edge states have been proposed to explain efficient exciton dissociation observed in MHPs. However, neither mechanism has directly validated. By analyzing temperature dependence exciton's linear quadratic Stark shifts, this study reveals another important aspect charge–lattice interactions....
Alloying mixed ratios of elements into the halide perovskite (HP) structure has proven to be an effective method tuning these materials' structural and electronic properties for photovoltaic other optoelectronic applications. However, standard spectroscopies used characterize HP alloys such as absorption photoluminescence are limited in their ability detect disorder phase segregation within structure. Here, we 2D a greater degree by using electroabsorption spectroscopy study thin films with...
Abstract Coulomb interactions govern most optoelectronic properties in semiconductors including bandgap, excitons, polaron formation, light absorption, interaction of carriers with defects, charge and energy transport. A clear signature the strength many-body is exciton binding (Eb). As such, importance Eb perhaps second only to fundamental band gap (Eg) understanding physics efficiency low-dimensional semiconductors. However, despite their importance, Eg are difficult measure. Here, by...
Coulomb interactions govern most optoelectronic properties in semiconductors including bandgap, excitons, polaron formation, light absorption, interaction of carriers with defects, charge and energy transport. A clear signature the strength many-body is exciton binding (Eb) importance Eb perhaps second only to fundamental band gap (Eg) determining low-dimensional semiconductors. However, despite their importance, Eg have still evaded consensus literature for even commonly studied 2D halide...
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As the field of metal halide perovskites (MHP) matures, state-of-the-art techniques to measure basic properties such as band gap and exciton binding energy continue produce inconsistent values. This issue is persistent even for 2D MHPs wherein large separation between continuum states should make measurements more straightforward. In this study, we revert established theory a Wannier in uniform electric analyze electroabsorption response an archetypal MHP system, phenethylammonium lead...