Evidence of Sequential Carrier Escape in III-V p-i-n Multi-Quantum Well Solar Cells

2007 ◽  
Vol 1031 ◽  
Author(s):  
Andenet Alemu ◽  
Jose A. H. Coaquira ◽  
Alex Freundlich
Keyword(s):  
Activation Energy ◽  
Solar Cells ◽  
Quantum Well ◽  
Quantum Wells ◽  
Effective Potential ◽  
Radiative Recombination ◽  
Energy Levels ◽  
Photoluminescence Intensity ◽  
Carrier Escape ◽  
Multi Quantum Well

AbstractSeveral InAsP/InP p-i-n Multi-Quantum Well (MQW) solar cells, only differing by their MQW region composition and geometry, were investigated. For each sample, the Arrhenius plot of the temperature related variation of the photoluminescence intensity was used to deduce the radiative recombination activation energy. The electron and holes confinement energy levels in the quantum wells and the associated effective potential barriers seen by each carrier were theoretically calculated. Carrier escape times were also estimated for each carrier. The fastest escaping carrier is found to display an effective potential energy barrier equal to the experimentally determined photoluminescence activation energy. This not only shows that the temperature related radiative recombination extinction process is driven by the carrier escape mechanism but also that the carriers escape process is sequential. Moreover, a discrepancy in device performance is directly correlated to the nature of the fastest escaping carrier.

scholarly journals A III-nitride nanowire solar cell fabricated using a hybrid coaxial and uniaxial InGaN/GaN multi quantum well nanostructure

RSC Advances ◽  
2018 ◽  
Vol 8 (37) ◽  
pp. 20585-20592 ◽  
Author(s):  
Ji-Hyeon Park ◽  
R. Nandi ◽  
Jae-Kwan Sim ◽  
Dae-Young Um ◽  
San Kang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Quantum Well ◽  
Quantum Wells ◽  
Cap Layer ◽  
Multi Quantum Well

Solar cells fabricated with hybrid nanowires comprising InGaN/GaN uniaxial and coaxial multi-quantum wells with an InGaN nano-cap layer.

scholarly journals Analytical Models of Bulk and Quantum Well Solar Cells and Relevance of the Radiative Limit

2012 ◽  
pp. 59-77 ◽  
Author(s):  
James P. Connolly
Keyword(s):  
Solar Cells ◽  
Quantum Well ◽  
Space Charge ◽  
Radiative Recombination ◽  
Light Trapping ◽  
Open Circuit ◽  
Analytical Models ◽  
Injection Currents ◽  
Photon Recycling ◽  
Open Circuit Voltages

The analytical modelling of bulk and quantum well solar cells is reviewed. The analytical approach allows explicit estimates of dominant generation and recombination mechanisms at work in charge neutral and space charge layers of the cells. Consistency of the analysis of cell characteristics in the light and in the dark leaves a single free parameter, which is the mean Shockley-Read-Hall lifetime. Bulk PIN cells are shown to be inherently dominated by non-radiative recombination as a result of the doping related non-radiative fraction of the Shockley injection currents. Quantum well PIN solar cells on the other hand are shown to operate in the radiative limit as a result of the dominance of radiative recombination in the space charge region. These features are exploited using light trapping techniques leading to photon recycling and reduced radiative recombination. The conclusion is that the mirror backed quantum well solar cell device features open circuit voltages determined mainly by the higher bandgap neutral layers, with an absorption threshold determined by the lower gap quantum well superlattice.

Multi-quantum-well quantum dots with stable dual emission

Nanoscale ◽  
2019 ◽  
Vol 11 (17) ◽  
pp. 8475-8484 ◽  
Author(s):  
Weishuo Xing ◽  
Xinsu Zhang ◽  
Chong Geng ◽  
Yangyang Xie ◽  
Yuchen Deng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Well ◽  
Quantum Wells ◽  
Excitation Power ◽  
Dual Emission ◽  
Multi Quantum Well ◽  
Exciton Distribution

MQW-QDs with stable dual emission versus excitation power are achieved via balancing exciton distribution in adjacent quantum wells.

Quantum-Well Solar Cells

MRS Bulletin ◽  
1993 ◽  
Vol 18 (10) ◽  
pp. 51-55 ◽  
Author(s):  
Keith Barnham ◽  
Jenny Barnes ◽  
Guido Haarpaintner ◽  
Jenny Nelson ◽  
Mark Paxman ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Quantum Well ◽  
Quantum Wells ◽  
Forward Bias ◽  
Flat Band ◽  
Output Current ◽  
Novel Approach ◽  
Modulator Structure ◽  
Conventional Cell

The best present-day single-bandgap solar cells have efficiencies around 20–25%. However, the Carnot efficiency of the earth-sun system is 95%, so there is considerable potential for improvement. The fundamental efficiency limitation in a conventional solar cell results from the tradeoff between a low bandgap which maximizes light absorption and hence output current and a high bandgap which maximizes output voltage. As a result, the maximum theoretical efficiency of a conventional solar cell is around 30% in unconcentrated sunlight at a bandgap close to that of GaAs.The quantum-well solar cell is a novel approach to higher efficiency. In its simplest form, shown in Figure 1, it consists of a multiquantum-well (MQW) system in the undoped region of a p-i-n solar cell. For light with energy greater than the band-gap Eg, the quantum-well cell behaves like a conventional cell. However, light with energy below Eg can be absorbed in the quantum wells. Our studies show that if the material quality is good, the electrons and holes escape from the wells and contribute to a higher output current at a voltage between that of the barrier and well material. In AlGaAs/GaAs test devices, we have obtained efficiency enhancements of a factor of more than two when cells with quantum wells are compared with identical cells without wells.The structure in Figure 1 is, of course, essentially similar to the MQW photodiode or modulator structure that operates in reverse bias, and the quantum-well laser that operates in forward bias beyond flat band.

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