Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell

  title={Peak External Photocurrent Quantum Efficiency Exceeding 100\% via MEG in a Quantum Dot Solar Cell},
  author={Octavi E. Semonin and Joseph M. Luther and Sukgeun Choi and Hsiang‐Yu Chen and Jianbo Gao and Arthur J. Nozik and Matthew C. Beard},
  pages={1530 - 1533}
An experimental solar cell productively uses an extra fraction of high-energy light typically lost as heat. Multiple exciton generation (MEG) is a process that can occur in semiconductor nanocrystals, or quantum dots (QDs), whereby absorption of a photon bearing at least twice the bandgap energy produces two or more electron-hole pairs. Here, we report on photocurrent enhancement arising from MEG in lead selenide (PbSe) QD-based solar cells, as manifested by an external quantum efficiency (the… 
Multiple exciton generation for photoelectrochemical hydrogen evolution reactions with quantum yields exceeding 100
Multiple exciton generation (MEG) in quantum dots (QDs) has the potential to greatly increase the power conversion efficiency in solar cells and in solar-fuel production. During the MEG process, two
Lead Telluride Quantum Dot Solar Cells Displaying External Quantum Efficiencies Exceeding 120%
PbTe quantum dot-based solar cells are demonstrated, which produce extractable charge carrier pairs with an external quantum efficiency above 120%, and an internal quantum efficiency exceeding 150%, and resolved the charge carrier kinetics on the ultrafast time scale.
Enhanced Open-Circuit Voltage of PbS Nanocrystal Quantum Dot Solar Cells
There is a tremendous opportunity for improvement of Voc to values greater than 1 V by using smaller QDs in QD solar cells, compared with the theoretical upper-limit obtained from one diode modeling of the cells with different Eg.
Ultimate Charge Extraction of Monolayer PbS Quantum Dot for Observation of Multiple Exciton Generation.
  • So-yeon Park, Se-Hoon Han, +4 authors H. Jung
  • Medicine, Materials Science
    Chemphyschem : a European journal of chemical physics and physical chemistry
  • 2019
It is demonstrated that excess charge carriers produced via MEG can be efficiently extracted using monolayer PbS QDs, which can provide a simple method to find suitable CQD materials and design interface engineering for MEG.
Optoelectronic engineering of colloidal quantum-dot solar cells beyond the efficiency black hole: a modeling approach
Colloidal quantum dot (CQD) solar cells have been under the spotlight in recent years mainly due to their potential for low-cost solution-processed fabrication and efficient light harvesting through
Zinc dopant inspired enhancement of electron injection for CuInS2 quantum dot-sensitized solar cells
After being doped with zinc, CuInS2 quantum dots (QDs) exhibit desired tunable optical and electronic properties, more specifically, photoluminescence emission and band gap. The former is mainly due
Next Generation Photovoltaics Based on Multiple Exciton Generation in Quantum Dot Solar Cells
Next Generation solar cells based onMultiple Exciton Generation (MEG) in semiconductorquantum dots (QDs) are described. This application of QDs depends upon efficient MEG in QDs incorporated into PV
Control of hot-carrier relaxation for realizing ideal quantum-dot intermediate-band solar cells
Comparison of two- and three-beam photocurrent spectra obtained by subbandgap excitation reveals that the QD TS-TPA efficiency is improved significantly by suppressing the relaxation of hot TS- TPA carriers to unoccupied shallow InAs quantum structure states.
Boosting the efficiency of quantum dot sensitized solar cells through modulation of interfacial charge transfer.
  • P. Kamat
  • Materials Science, Medicine
    Accounts of chemical research
  • 2012
The power conversion efficiency for liquid junction and solid state quantum dot solar cells, which is in the range of 5-6%, represents a significant advance toward effective utilization of nanomaterials for solar cells.
Near‐Infrared Photoactive Semiconductor Quantum Dots for Solar Cells
  • Ru Zhou, Jun Xu, +5 authors Lianzhou Wang
  • Materials Science
    Advanced Energy Materials
  • 2021
Semiconductor quantum dots (QDs) are nanocrystals whose excitons are bound in 3D space. Owning to their remarkable quantum confinement effect, QDs exhibit a discontinuous electronic energy level


Quantum dot solar cells
Abstract Quantum dot (QD) solar cells have the potential to increase the maximum attainable thermodynamic conversion efficiency of solar photon conversion up to about 66% by utilizing hot
Multiple Exciton Generation in Semiconductor Quantum Dots.
  • M. Beard
  • Physics, Medicine
    The journal of physical chemistry letters
  • 2011
If the MEG efficiency can be further enhanced and charge separation and transport can be optimized within QD films, then QD solar cells can lead to third-generation solar energy conversion technologies.
Comparing multiple exciton generation in quantum dots to impact ionization in bulk semiconductors: implications for enhancement of solar energy conversion.
It is demonstrated that the fundamental unit of energy required to produce each electron-hole pair in a given QD is the band gap energy, and the research challenges associated with achieving the maximum benefit of MEG in solar energy conversion are discussed since the threshold and efficiency are mathematically related.
Carrier multiplication in bulk and nanocrystalline semiconductors: Mechanism, efficiency, and interest for solar cells
Carrier multiplication (CM), the possibility to generate more than one exciton in a semiconductor quantum dot (QD) after absorption of a single photon has been intensely debated in recent years.
Determining the internal quantum efficiency of PbSe nanocrystal solar cells with the aid of an optical model.
On the basis of the magnitudes and shapes of the IQE spectra, it is concluded that the 1,2-ethanedithiol treated NC devices studied here do not produce appreciable MEG photocurrent.
Multiple Exciton Collection in a Sensitized Photovoltaic System
A photoelectrochemical system composed of PbS nanocrystals chemically bound to TiO2 single crystals is used to demonstrate the collection of photocurrents with quantum yields greater than one electron per photon, which has implications for increasing the efficiency of photovoltaic devices by avoiding losses resulting from the thermalization of photogenerated carriers.
Enhanced multiple exciton generation in quasi-one-dimensional semiconductors.
A significant enhancement of multiple exciton generation in PbSe quasi-one-dimensional semiconductors (nanorods) over zero-dimensional nanostructures (nanocrystals) is reported, characterized by a 2-fold increase in efficiency and reduction of the threshold energy to (2.23 ± 0.03)E(g), which approaches the theoretical limit of 2E( g).
Apparent versus true carrier multiplication yields in semiconductor nanocrystals.
It is shown that uncontrolled photocharging of the nanocrystal core can lead to exaggeration of the Auger decay component and, as a result, significant deviations of the apparent CM efficiencies from their true values are observed.
Multiple exciton generation in films of electronically coupled PbSe quantum dots.
It is demonstrated that the MEG efficiency in PbSe does not decrease when the QDs are treated with hydrazine, which has been shown to greatly enhance carrier transport in P bSe QD films by decreasing the interdot distance.
Colloidal Quantum-Dot Photodetectors Exploiting Multiexciton Generation
A class of solution-processed photoconductive detectors, sensitive in the ultraviolet, visible, and the infrared, are reported, in which the internal gain is dramatically enhanced for photon energies Ephoton greater than 2.7 times the quantum-confined bandgap Ebandgap.