A5018426124- Semiconductor Quantum Structures and Devices
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- solar cell performance optimization
- Nanowire Synthesis and Applications
- Semiconductor materials and interfaces
- Advanced Semiconductor Detectors and Materials
- Perovskite Materials and Applications
- Silicon and Solar Cell Technologies
- Advancements in Semiconductor Devices and Circuit Design
- Quantum and electron transport phenomena
- Semiconductor Lasers and Optical Devices
- Nanocluster Synthesis and Applications
- Near-Field Optical Microscopy
- Thermal Radiation and Cooling Technologies
- Spectroscopy and Laser Applications
- Advanced Thermoelectric Materials and Devices
- Ga2O3 and related materials
- Solar Thermal and Photovoltaic Systems
- Electrostatics and Colloid Interactions
- Laser Material Processing Techniques
- Silicon Nanostructures and Photoluminescence
- 2D Materials and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Molecular Junctions and Nanostructures
IMDEA Energy Institute
2012-2024
Universidad Politécnica de Madrid
2013-2023
Universidade Nova de Lisboa
2021-2023
Institute of Photonic Sciences
2018-2020
Barcelona Institute for Science and Technology
2018
Shanghai Institute for Science of Science
2018
Institute of Science and Technology
2018
University College London
2014
Universidad Autónoma del Estado de Morelos
2009
The intermediate band solar cell (IBSC) has drawn the attention of scientific community as a means to achieve high-efficiency cells. Complete IBSC devices have been manufactured using quantum dots, highly mismatched alloys, or bulk materials with deep-level impurities. Characterization these led, among other experimental results, demonstration two operating principles an IBSC: production photocurrent from absorption below bandgap energy photons and preservation output voltage cell. This...
Optical sensing in the mid- and long-wave infrared (MWIR, LWIR) is of paramount importance for a large spectrum applications including environmental monitoring, gas sensing, hazard detection, food product manufacturing inspection, so forth. Yet, such to date are served by costly complex epitaxially grown HgCdTe quantum-well quantum-dot photodetectors. The possibility exploiting low-energy intraband transitions make colloidal quantum dots (CQD) an attractive low-cost alternative expensive low...
We report, for the first time, about an intermediate band solar cell implemented with InAs/AlGaAs quantum dots whose photoresponse expands from 250 to ∼6000 nm. To our knowledge, this is broadest efficiency reported date a and demonstrates that capable of producing photocurrent when illuminated photons energy equals lowest gap. show experimental evidence indicating result in agreement theory cell, according which generation recombination between valence makes detectable.
Current prototypes of quantum-dot intermediate band solar cells suffer from voltage reduction due to the existence thermal carrier escape. An enlarged subbandgap E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> would not only minimize this problem but lead a bandgap distribution that exploits more efficiently spectrum. In study, we demonstrate InAs/InGaP QD-IBSC with following distribution:...
Abstract In the quest for high‐efficiency photovoltaics (PV), intermediate band solar cell (IBSC) was proposed in 1997 as an alternative to tandem cells. The IBSC offers 63% efficiency under maximum concentration using a single semiconductor material. This limit attracted attention of PV community, yielding numerous (IB) studies and prototypes employing plethora candidate IB materials. As consequence, principles operation have been demonstrated, particularities difficulties inherent each...
Recent approaches to develop infrared photodetectors characterized by high sensitivities, broadband spectral coverage, easy integration with silicon electronics and low cost have been based on hybrid structures of transition metal dichalcogenides (TMDCs) PbS colloidal quantum dots (CQDs). However, date, such reported sensitivity up 1.5 $\mu$m. Here we extend the coverage this technology towards 2 $\mu$m demonstrating for first time compelling performance responsivities 1400 A/W at 1.8 1V...
The realization of high efficiency quantum dot intermediate band solar cells is challenging due to the thermally activated charge escaping at temperatures. enhancement in short circuit current largely undermined by voltage loss. In this paper, InAs/GaAs with direct Si doping dots are studied. open improved increasing concentration dots. recovery as large 105 mV measured. This attributed suppressed thermal from coupling supported external and photoluminescence measurements.
A colloidal deposition technique is presented to construct long-range ordered hybrid arrays of self-assembled quantum dots and metal nanoparticles. Quantum are promising for novel opto-electronic devices but, in most cases, their optical transitions interest lack sufficient light absorption provide a significant impact implementation. potential solution couple the with localized plasmons The extreme confinement near-field produced by nanoparticles can potentially boost up two orders...
Colloidal quantum dot photovoltaics with a bandgap of 0.7 eV demonstrate potential to harness the infrared solar spectrum as well in waste heat recovery.
Materials with optical gain in the infrared are of paramount importance for communications, medical diagnostics, and silicon photonics. The current technology is based either on costly III–V semiconductors that not monolithic to CMOS or Er-doped fiber does make use full transparency window. Colloidal quantum dots (CQDs) offer a unique opportunity as an medium view their tunable bandgap, solution processability, compatibility. 8-fold degeneracy CQDs Pb-chalcogenides has hindered demonstration...
In this paper, a model for intermediate band solar cells is built based on the generally understood physical concepts ruling semiconductor device operation, with special emphasis behavior at low temperature. The compared to JL-VOC measurements concentrations up about 1000 suns and temperatures down 20 K, as well of radiative recombination obtained from electroluminescence. agreement reasonable. It found that main reason reduction open circuit voltage an operational bandgap, but effect...
Quantum-dot (QD) intermediate-band (IB) materials are regarded as promising candidates for high-efficiency photovoltaics. The sequential two-step two-photon absorption processes that take place in these have been proposed to develop solar cells and infrared (IR) photodetectors. In this work, we experimentally theoretically study the interrelation of absorptivity with transitions carriers from IB type-II GaSb/GaAs QD devices. Our devices exhibit three optical band gaps with:...
Steady-state access to intraband transitions in colloidal quantum dots (CQDs), via doping, permits exploitation of the electromagnetic spectrum at energies below band gap. CQD optoelectronics allows envisaging cheap mid- and long-wavelength infrared photodetectors light-emitting devices, which today employ epitaxial materials. As devices start emerge, thorough studies basic properties different materials are needed guide technological research. In this work, we investigate size temperature...
Several groups have reported on intermediate band solar cells (IBSC) fabricated with InAs/GaAs quantum dots (QD) which exhibit efficiencies (QE) for sub-bandgap photon energies. However, this QE is produced by the absorption of photons only through valence (VB) to (IB) transitions. The that energy in IB conduction (CB) transitions weak and usually replaced carrier escape. This mechanism incompatible preservation output voltage, therefore, it cannot lead high predicted IBSC model. In work, we...
Perovskite nanocrystal light-emitting diodes (LEDs) employing architecture comprising a ZnO nanoparticles electron-transport layer and conjugated polymer hole-transport have been fabricated. The obtained LEDs demonstrate maximum external-quantum-efficiency of 6.04%, luminance 12998 Cd/m2 stable electroluminescence at 519 nm. Importantly, such high efficiency brightness achieved by solution processed transport layers, formamidinium lead bromide nanocrystals (CH(NH2)2PbBr3 NCs) synthesized...
In the last decade several prototypes of intermediate band solar cells (IBSCs) have been manufactured. So far, most these based on InAs/GaAs quantum dots (QDs) in order to implement IB material. The key operation principles theory are two photon sub-bandgap (SBG) photocurrent, and output voltage preservation, both experimentally demonstrated at low temperature. At room temperature (RT), however, thermal escape/relaxation between conduction (CB) prevents preservation. To improve this...
The concept of intermediate band solar cell (IBSC) is, apparently, simple to grasp. However, since the idea was proposed, our understanding has improved and some concepts can now be explained more clearly than when initially introduced. Clarifying these is important, even if they are well known for advanced researcher, so that research efforts driven in right direction from start. six pieces this work are: Does a miniband need formed IBSC implemented with quantum dots? What problems each...
To achieve high efficiency, the intermediate band (IB) solar cell must generate photocurrent from sub-bandgap photons at a voltage higher than that of single contributing photon. latter, it is necessary IB levels be properly isolated valence and conduction bands. We prove this not case for cells formed with confined InAs quantum dots (QDs) in GaAs grown so far due to strong density internal thermal transition energies involved. counteract this, QD smaller.
In this work, we study type-II GaSb/GaAs quantum-dot intermediate band solar cells (IBSCs) by means of quantum efficiency (QE) measurements. We are able, for the first time, to measure an absolute QE which clearly reveals three characteristic bandgaps IBSC; E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> , xmlns:xlink="http://www.w3.org/1999/xlink">H</sub> and xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> found values 1.52, 1.02,...