Solar Cells Based on Quantum Dots: Multiple Exciton Generation and Intermediate Bands

MRS Bulletin ◽  
2007 ◽  
Vol 32 (3) ◽  
pp. 236-241 ◽  
Author(s):  
Antonio Luque ◽  
Antonio Martí ◽  
Arthur J. Nozik
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Single Photon ◽  
Quantum Yields ◽  
Bandgap Energy ◽  
Hot Electron ◽  
Electron Hole ◽  
Multiple Exciton Generation ◽  
Intermediate Band

AbstractSemiconductor quantum dots may be used in so-called third-generation solar cells that have the potential to greatly increase the photon conversion efficiency via two effects: (1) the production of multiple excitons from a single photon of sufficient energy and (2) the formation of intermediate bands in the bandgap that use sub-bandgap photons to form separable electron–hole pairs. This is possible because quantization of energy levels in quantum dots produces the following effects: enhanced Auger processes and Coulomb coupling between charge carriers; elimination of the requirement to conserve crystal momentum; slowed hot electron–hole pair (exciton) cooling; multiple exciton generation; and formation of minibands (delocalized electronic states) in quantum dot arrays. For exciton multiplication, very high quantum yields of 300–700% for exciton formation in PbSe, PbS, PbTe, and CdSe quantum dots have been reported at photon energies about 4–8 times the HOMO–LUMO transition energy (quantum dot bandgap), respectively, indicating the formation of 3–7 excitons/photon, depending upon the photon energy. For intermediate-band solar cells, quantum dots are used to create the intermediate bands from the con fined electron states in the conduction band. By means of the intermediate band, it is possible to absorb below-bandgap energy photons. This is predicted to produce solar cells with enhanced photocurrent without voltage degradation.

Investigation of Quantum Dot Solar Cell Device Performance

2013 ◽  
Vol 1551 ◽  
pp. 137-142
Author(s):  
Neil S. Beattie ◽  
Guillaume Zoppi ◽  
Ian Farrer ◽  
Patrick See ◽  
Robert W. Miles ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Solar Cell ◽  
Quantum Dot ◽  
Band Gap ◽  
Control Device ◽  
Open Circuit ◽  
Device Performance ◽  
Intermediate Band ◽  
Control Devices

ABSTRACTThe device performance of GaAs p-i-n solar cells containing stacked layers of self-assembled InAs quantum dots is investigated. The solar cells demonstrate enhanced external quantum efficiency below the GaAs band gap relative to a control device without quantum dots. This is attributed to the capture of sub-band gap photons by the quantum dots. Analysis of the current density versus voltage characteristic for the quantum dot solar cell reveals a decrease in the series resistance as the device area is reduce from 0.16 cm2 to 0.01 cm2. This is effect is not observed in control devices and is quantum dot related. Furthermore, low temperature measurements of the open circuit voltage for both quantum dot and control devices provide experimental verification of the conditions required to realise an intermediate band gap solar cell.

Stranski–Krastanov InAs/GaAsSb quantum dots coupled with sub-monolayer quantum dot stacks as a promising absorber for intermediate band solar cells

2017 ◽  
Vol 111 (7) ◽  
pp. 073103 ◽  
Author(s):  
Yeongho Kim ◽  
Il-Wook Cho ◽  
Mee-Yi Ryu ◽  
Jun Oh Kim ◽  
Sang Jun Lee ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Intermediate Band ◽  
Intermediate Band Solar Cells

scholarly journals Influence of Geometrical Shape on the Characteristics of the Multiple InN/InxGa1−xN Quantum Dot Solar Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1317
Author(s):  
Asmae El Aouami ◽  
Laura M. Pérez ◽  
Kawtar Feddi ◽  
Mohamed El-Yadri ◽  
Francis Dujardin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Conversion Efficiency ◽  
Current Knowledge ◽  
Indium Nitride ◽  
Multiple Quantum ◽  
Geometrical Shape ◽  
Intermediate Band ◽  
Quantum Dot Solar Cells

Solar cells that are based on the implementation of quantum dots in the intrinsic region, so-called intermediate band solar cells (IBSCs), are among the most widely used concepts nowadays for achieving high solar conversion efficiency. The principal characteristics of such solar cells relate to their ability to absorb low energy photons to excite electrons through the intermediate band, allowing for conversion efficiency exceeding the limit of Shockley–Queisser. IBSCs are generating considerable interest in terms of performance and environmental friendliness. However, there is still a need for optimizing many parameters that are related to the solar cells, such as the size of quantum dots, their shape, the inter-dot distance, and choosing the right material. To date, most studies have only focused on studying IBSC composed of cubic shape of quantum dots. The main objective of this study is to extend the current knowledge of IBSC. Thus, we analyze the effect of the shape of the quantum dot on the electronic and photonic characteristics of indium nitride and indium gallium nitride multiple quantum dot solar cells structure considering cubic, spherical, and cylindrical quantum dot shapes. The ground state of electrons and holes energy levels in quantum dot are theoretically determined by considering the Schrödinger equation within the effective mass approximation. Thus, the inter and intra band transitions are determined for different dot sizes and different inter dot spacing. Consequently, current–voltage (J-V) characteristic and efficiencies of these devices are evaluated and compared for different shapes. Our calculations show that, under fully concentrated light, for the same volume of different quantum dots (QD) shapes and a well determined In-concentration, the maximum of the photovoltaic conversion efficiencies reaches 63.04%, 62.88%, and 62.43% for cubic, cylindrical, and spherical quantum dot shapes, respectively.

AlGaInAs quantum dot solar cells: tailoring quantum dots for intermediate band formation

2012 ◽  
Vol 27 (3) ◽  
pp. 032002 ◽  
Author(s):  
C Schneider ◽  
S Kremling ◽  
N V Tarakina ◽  
T Braun ◽  
M Adams ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Band Formation ◽  
Intermediate Band ◽  
Quantum Dot Solar Cells

scholarly journals Theoretical Study of One-Intermediate Band Quantum Dot Solar Cell

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Abou El-Maaty Aly ◽  
Ashraf Nasr
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Quantum Dot ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Power Conversion ◽  
Maximum Efficiency ◽  
Total Output ◽  
Bandgap Energy ◽  
Intermediate Band

The intermediate bands (IBs) between the valence and conduction bands play an important role in solar cells. Because the smaller energy photons than the bandgap energy can be used to promote charge carriers transfer to the conduction band and thereby the total output current increases while maintaining a large open circuit voltage. In this paper, the influence of the new band on the power conversion efficiency for the structure of the quantum dots intermediate band solar cell (QDIBSC) is theoretically investigated and studied. The time-independent Schrödinger equation is used to determine the optimum width and location of the intermediate band. Accordingly, achievement of maximum efficiency by changing the width of quantum dots and barrier distances is studied. Theoretical determination of the power conversion efficiency under the two different ranges of QD width is presented. From the obtained results, the maximum power conversion efficiency is about 70.42% for simple cubic quantum dot crystal under full concentration light. It is strongly dependent on the width of quantum dots and barrier distances.

CONSTRUCTION COMPONENTS ENGINEERING IN INTERMEDIATE BAND SOLAR CELLS

2012 ◽  
Vol 26 (14) ◽  
pp. 1250090 ◽  
Author(s):  
N. E. GORJI ◽  
M. HOUSHMAND ◽  
S. S. DEHKORDI
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Filling Factor ◽  
High Efficiency ◽  
Low Cost ◽  
Maximum Efficiency ◽  
Maximum Point ◽  
Intermediate Band ◽  
Intermediate Band Solar Cells

The parameter electron filling factor can be taken as a scale for the electronic states in the intermediate band which should be de-localized and thus the unconfined electrons at the quantum dots. For three different value of electron filling factor, the sunlight concentration effect on the efficiency of a quantum dot solar cell is calculated. The maximum point of efficiency and optimum thickness of the cell obtained under three different sunlight concentrations. We show the importance of electron filling factor as a parameter to be more considered. This parameter can be controlled by the quantum dots size and distance between quantum dot layers in the active region. Analysis of above mentioned parameters suggest that to attain a maximum efficiency, the size of the quantum dots and the distance between the periodically arrayed dot layers have to be optimized. In addition, sunlight concentration is recommended as an effective approach to have high efficiency and low cost level solar cells.

scholarly journals Flexible and efficient perovskite quantum dot solar cells via hybrid interfacial architecture

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Long Hu ◽  
Qian Zhao ◽  
Shujuan Huang ◽  
Jianghui Zheng ◽  
Xinwei Guan ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
High Performance ◽  
Mechanical Stability ◽  
Mechanical Adhesion ◽  
Perovskite Quantum Dots ◽  
Efficient Charge ◽  
Photovoltaic Technologies

AbstractAll-inorganic CsPbI3 perovskite quantum dots have received substantial research interest for photovoltaic applications because of higher efficiency compared to solar cells using other quantum dots materials and the various exciting properties that perovskites have to offer. These quantum dot devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. We demonstrate higher mechanical endurance of quantum dot films compared to bulk thin film and highlight the importance of further research on high-performance and flexible optoelectronic devices using nanoscale grains as an advantage. Specifically, we develop a hybrid interfacial architecture consisting of CsPbI3 quantum dot/PCBM heterojunction, enabling an energy cascade for efficient charge transfer and mechanical adhesion. The champion CsPbI3 quantum dot solar cell has an efficiency of 15.1% (stabilized power output of 14.61%), which is among the highest report to date. Building on this strategy, we further demonstrate a highest efficiency of 12.3% in flexible quantum dot photovoltaics.

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