A new approach to modelling quantum dot concentrators

Chatten, Amanda J.; Barnham, K.W.J.; Buxton, Bernard F.; Ekins-Daukes, N. J.; Malik, Mohammad Azad

doi:10.1016/s0927-0248(02)00182-4

Cited by 100 publications

(52 citation statements)

References 9 publications

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“…However, conversion efficiency of QDSCs developed to date [12][13][14][15] has been limited, firstly by, the low fluorescence quantum yield of the commercially available visible-emitting QDs [16] and NIR-emitting QDs [17,18]. Secondly, the devices suffer from re-absorption losses at higher concentrations of QDs [19][20][21] due to significant, or even in some cases total, overlap of the absorption and primary emission spectra. Some of these problems could be addressed by exploiting plasmonic interaction between QDs and metal nanoparticles (MNPs).…”

Section: Quantum Dot Solar Concentrators (Qdsc)mentioning

confidence: 99%

“…This proved that QD concentration could be decreased, without compromising the total emission, using the plasmonic interaction of Au NPs in a luminescent solar concentrator. This would lead to a decrease of the re-absorption losses in a device, which primarily occurs due to higher concentration of luminescent species in luminescent solar concentrators [19][20][21]. It is reasonable to expect a change in the overall efficiency of a luminescent solar concentrator when this optimized QDs/Au NPs composite is used to fabricate the luminescent solar concentrator, as the overall optical efficiency mainly depends on the total emission of luminescent species.…”

Section: Fluorescence Emission Of Qd/au Np Compositementioning

confidence: 99%

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Enhanced quantum dot emission for luminescent solar concentrators using plasmonic interaction

Chandra¹,

Doran²,

McCormack

et al. 2012

Solar Energy Materials and Solar Cells

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101

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a b s t r a c tPlasmonic excitation enhanced fluorescence of CdSe/ZnS core-shell quantum dots (QDs) in the presence of Au nanoparticles (NPs) has been studied for application in quantum dot solar concentrator (QDSC) devices. We observe that there is an optimal concentration of Au NPs that gives a maximum 53% fluorescence emission enhancement for the particular QD/Au NP composite studied. The optimal concentration depends on the coupling and spacing between neighboring QDs and Au NPs. We show the continuous transition from fluorescence enhancement to quenching, depending on Au NP concentration. The locally enhanced electromagnetic field induced by the surface plasmon resonance in the Au NPs leads to an increased excitation rate for the QDs. This is evidenced by excitation wavelength dependent fluorescence enhancement, where the locally enhanced field around the Au NPs is more pronounced close to the surface plasmon resonance (SPR) wavelength. However, at higher concentrations of Au NPs non-radiative energy transfer from the QDs to the Au NPs particles leads to a decrease of the emission, which is confirmed by detection of both a double exponential lifetime decay in, and a decrease in the lifetime of the QDs. The overall fluorescence emission enhancement depends on these competing effects; increased excitation rate and non-radiative energy transfer.

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Section: Quantum Dot Solar Concentrators (Qdsc)mentioning

confidence: 99%

Section: Fluorescence Emission Of Qd/au Np Compositementioning

confidence: 99%

Enhanced quantum dot emission for luminescent solar concentrators using plasmonic interaction

Chandra¹,

Doran²,

McCormack

et al. 2012

Solar Energy Materials and Solar Cells

Self Cite

101

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“…Spectral conversion based on organic dye molecules has been attempted but the dyes were not able to achieve very high quantum efficiencies, were unstable and exhibited limited absorption bandwidths [4]. However, solutions containing QD are very efficient (near 60% quantum efficiency) at absorbing spectral energy from wavelengths less than 450 nm and can convert them through photoluminescence to visible energy at 620nm, which is near the band-gap of many c-Si solar cells [5][6][7][8][9]. Quantum dots are a cluster of tightly packed atoms as shown in Figure 1.…”

Section: Quantum Dotsmentioning

confidence: 99%

Utilizing Quantum Dots to Enhance Solar Spectrum Conversion Efficiencies for Photovoltaics

et al. 2008

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Silicon-based photovoltaics typically convert less than 30% of the solar spectrum into usable electric power. This study explores the utilization of CdSe based quantum dots as spectral converters that absorb the under utilized UV portion of the solar spectrum and fluoresce at wavelengths near the band-gap of silicon-based solar cells. A flexible 1 mm thick thin-film structure that contains an array of microfluidic channels is designed and fabricated in polydimethylsiloxane (PDMS) using soft-lithographic techniques. The channels are approximately 85 microns wide by 37 microns tall and are filled with a solution containing the quantum dots. The thin-film structure can easily be attached to the surface of a single-junction solar cell. As a result, solar energy striking the coated solar cell with wavelengths less than 450 nm, which would normally experience low conversion efficiency, are absorbed by the quantum dots which fluoresce at 620nm. The high energy photons are converted to photons near the band-gap which increase the overall conversion efficiency of the solar cell. The quantum dots employed in this study are fabricated with a CdSe core (5.2 nm) and a ZnS outer shell and they exhibit a 25 nm hydrodynamic diameter. The UV-VIS spectral transmission properties of PDMS, along with its refractive index, are determined in order to characterize the spectral conversion efficiency of the thin-film structure. A model is developed to predict the optimum path length and concentration of quantum dots required to improve the power output of an amorphous silicon solar cell by 10%. PHOTOVOLTAIC TECHNOLOGYPhotovoltaic solar cells are commonly employed to harness the enormous energy (600-800 watts/m 2 ) that strikes the earth each day from the sun. The first silicon solar cell was developed at Bell Labs in 1954 and there has been a steady increase in the utilization of this sustainable energy source over the past 50 years [1]. Today, only 0.03% of the world's total power requirements are provided by the conversion of solar energy into electrical power [2]. One of the most cost effective implementations involves the utilization of crystalline silicon with conversion efficiencies typically around 15% yielding power production rates of around $0.25/kWh, which is still high compared to $0.05/kWh for coal or gas fired power plants [2]. Over 90% of the photovoltaic power produced today is from single crystal silicon based panels; however, first generation silicon based solar cells do not utilize all of the radiant energy that is provided by the sun. Specifically, wavelengths below 450 nanometers are not converted effectively into usable electrical power and as much as 39% of the sun's energy is under utilized [3]. This research focuses on developing a method for improving solar cell efficiency by 10% through the process of spectral conversion, which would thereby make it competitive with thirdgeneration photovoltaics based on multi-junction thin films. The spectral conversion technique examined in this study employs an aque...

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“…The analytical equations presented were solved for the simplified case of a semi-infinite rod. Most modern approaches to quantification of self-absorption are carried out with thermodynamic calculations [8][9][10], analytical models based on the Beer-Lambert law [11,12], or using Monte Carlo (MC) simulations [13][14][15][16][17][18][19][20], also referred to as raytracing. While MC simulations are relatively easy to implement, they rely on random numbers to calculate physical effects.…”

Section: Introductionmentioning

confidence: 99%

Rapid optimization of large-scale luminescent solar concentrators: evaluation for adoption in the built environment

2017

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A new approach to modelling quantum dot concentrators

Cited by 100 publications

References 9 publications

Enhanced quantum dot emission for luminescent solar concentrators using plasmonic interaction

Enhanced quantum dot emission for luminescent solar concentrators using plasmonic interaction

Utilizing Quantum Dots to Enhance Solar Spectrum Conversion Efficiencies for Photovoltaics

Rapid optimization of large-scale luminescent solar concentrators: evaluation for adoption in the built environment

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