A5084320529- Quantum Dots Synthesis And Properties
- Silicon Nanostructures and Photoluminescence
- TiO2 Photocatalysis and Solar Cells
- Photochemistry and Electron Transfer Studies
- Light effects on plants
- Nanowire Synthesis and Applications
- Thin-Film Transistor Technologies
- 2D Materials and Applications
- Greenhouse Technology and Climate Control
- Conducting polymers and applications
- Silicon and Solar Cell Technologies
- Photonic and Optical Devices
- solar cell performance optimization
- Perovskite Materials and Applications
- ZnO doping and properties
- Ga2O3 and related materials
- Terahertz technology and applications
- Chalcogenide Semiconductor Thin Films
- Copper-based nanomaterials and applications
- Thermal Radiation and Cooling Technologies
- Leaf Properties and Growth Measurement
- Graphene research and applications
- Transition Metal Oxide Nanomaterials
- Growth and nutrition in plants
- Organic Electronics and Photovoltaics
UbiQD (United States)
2018-2022
Institute for Basic Science
2019
Colorado School of Mines
2009-2016
National Renewable Energy Laboratory
2012-2016
Building-integrated sunlight harvesting utilizing laminated glass luminescent solar concentrators (LSCs) is proposed. By incorporating high quantum yield (>90%), NIR-emitting CuInS2/ZnS dots into the polymer interlayer between two sheets of low-iron float glass, a record optical efficiency 8.1% demonstrated for 10 cm × device that transmits ∼44% visible light. After completing prototypes by attaching silicon cells along perimeter device, electrical power conversion was certified at 2.2% with...
We have synthesized alkylselenide reagents to replace the native oleate ligand on PbSe quantum dots (QDs) in order investigate effect of surface modification their stoichiometry, photophysics, and air stability. The reagent removes all QD results Se addition; however, complete enrichment does not occur, achieving a 53% decrease amount excess Pb for 2 nm diameter QDs 23% 10 QDs. Our analysis suggests that preferentially binds {111} faces, which are more prevalent smaller find attachment...
Abstract Bioregenerative life-support systems (BLSS) involving plants will be required to realize self-sustaining human settlements beyond Earth. To improve plant productivity in BLSS, the quality of solar spectrum can modified by lightweight, luminescent films. CuInS 2 /ZnS quantum dot (QD) films were used down-convert ultraviolet/blue photons red emissions centered at 600 and 660 nm, resulting increased biomass accumulation romaine lettuce. All growth parameters, except for spectral...
Abstract Carrier multiplication (CM) is a process in which high-energy free carriers relax by generation of additional electron-hole pairs rather than heat dissipation. CM promising disruptive improvements photovoltaic energy conversion and light detection technologies. Current state-of-the-art nanomaterials including quantum dots carbon nanotubes have demonstrated CM, but are not satisfactory owing to high-energy-loss inherent difficulties with carrier extraction. Here, we report van der...
We report size-dependent exciton formation dynamics within colloidal silicon quantum dots (Si QDs) using time-resolved terahertz (THz) spectroscopy measurements. THz photoconductivity measurements are used to distinguish the initially created hot carriers from excitons that form at later times. At early pump/probe delays, revealed by temporal evolution of transmission. find an increase in time, ∼500 ∼900 fs, as Si QD diameter is reduced 7.3 3.4 nm and all sizes exhibit slower hot-carrier...
While luminescent concentrators (LCs) are mainly designed to harvest sunlight and convert its energy into electricity, the same concept can be advantageous in alternative applications. Examples of such applications demonstrated here by coupling edge-guided light high-performance LCs based on CuInSexS2-x/ZnS quantum dots optical fibers with emission covering visible-to-NIR spectral regions. In particular, a cost-efficient, miniature broadband source for medical diagnostics,...
Laminated-glass, luminescent solar concentrators (LSCs) offer localized and sustainable power generation combined with the customizable transparency needed for windows. Successful commercial deployment of LSC technology depends on demonstration economically viable efficiency, while maintaining excellent aesthetics. In this work, multiple-interlayer CuInS2/ZnS quantum dot (QD) devices comprised laminated glass are presented. Three-interlayer designs demonstrated a certified electrical...
While luminescent solar concentrators (LSCs) have been researched for several decades, there is still a lack of commercially available systems, mostly due to scalability, performance, aesthetics, or some combination these challenges. These obstacles can be overcome by the systematic optimization laminated glass LSC design, demonstrated herein. In particular, we first show that it possible improve optical and electrical efficiencies an fine-tuned constituent fluorophore-containing interlayer...
The spectral quality of sunlight reaching plants remains a path for optimization in greenhouse cultivation. Quantum dots represent novel, emission-tunable luminescent material optimizing the spectrum greenhouses with minimal intensity loss, ultimately enabling improved light use efficiency plant growth without requiring electricity. In this study, films containing CuInS 2 /ZnS quantum were utilized to absorb and convert ultraviolet blue photons from photoluminescent emission centered at 600...
We simultaneously determined the charge carrier mobility and picosecond to nanosecond dynamics of isolated silicon nanowires (Si NWs) nanocrystals NCs) using time-resolved terahertz spectroscopy. then compared these results data measured on bulk c-Si as a function excitation fluence. find >1 ns lifetimes in Si NWs that are dominated by surface recombination with velocities (SRV) between ∼1100-1700 cm s(-1) depending process conditions. The NCs have markedly different decay dynamics....
We report on the ultrafast carrier dynamics in hydrogenated nanocrystalline silicon (nc$\ensuremath{-}$Si:H) using time-resolved terahertz spectroscopy. Photoexcitation at 407 nm primarily produces charge carriers $a\ensuremath{-}$Si phase, but they undergo a rapid electron transfer to $c\ensuremath{-}$Si phase prior complete thermalization into band-tail states of $a\ensuremath{-}$Si. studied range nc$\ensuremath{-}$Si:H samples with varying crystalline volume fractions (${X}_{c}$) and...
We report on the growth of single-crystal ZnO nanosheets without stacking faults by Au-seeded pulsed laser deposition in a 0.5 mbar pure oxygen ambient, with their direction inclined to ZnO[0001] crystalline axis. Changing ambient 5% and 95% argon at same total pressure led formation [0001]-oriented single-crystalline nanowires. propose mechanism for based superposition catalyst-assisted beneath Au droplet asymmetric radial due enhanced rates exposed ZnO{0001} sidewall facets. The facets...
Carrier multiplication (CM), a photo-physical process to generate multiple electron-hole pairs by exploiting excess energy of free carriers, is explored for efficient photovoltaic conversion photons from the blue solar band, predominantly wasted as heat in standard cells. Current state-of-the-art approaches with nanomaterials have demonstrated improved CM but are not satisfactory due high loss and inherent difficulties carrier extraction. Here, we report ultra-efficient van der Waals (vdW)...
Abstract Bioregenerative life-support systems (BLSS) involving plants will be required to realize self-sustaining human settlements beyond Earth. To improve plant photosynthetic efficiency in BLSS, the quality of solar spectrum can modified by lightweight, luminescent films. CuInS 2 /ZnS quantum dot (QD) films with peak emissions at 600 and 660 nm were used redshift ultraviolet blue photons increase biomass accumulation red romaine lettuce. Plant growth parameters, except spectral quality,...