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Influence of Chirped DBR Reflector on the Absorption Efficiency of Multi-nanolayer Photovoltaic Structures: Wavelength-scale Analysis by the Method of Single Expression

Baghdasaryan H., Knyazyan T., Hovhannisyan T., Mardoyan G., Marciniak M., Benson T.

Journal of Telecommunications and Information Technology

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2017

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nr 3

99--106

EN

An electromagnetic wavelength-scale analysis of the optical characteristics of multi-nanolayer photovoltaic (PV) structures: without an antireflection coating, with an antireflection coating on the top of the structure, and with both the antireflection coating on the top and a broadband non-periodic (chirped) distributed Bragg reflector (DBR) on the bottom of the structure is performed. All the PV structures studied are based on a Si p-i-n type absorber supported by a metallic layer (Cu) and SiO2 substrate. The top-to-bottom electromagnetic analysis is performed numerically by the method of single expression (MSE). Absorbing and reflecting characteristics of the multi-nanolayer PV structures are obtained. The influence of the thicknesses and permittivities of the layers of the PV structures on the absorbing characteristics of the structures is analyzed to reveal favourable configurations for enhancement of their absorption efficiency. The localizations of the electric component of the optical field and the power flow distribution within all the PV structures considered are obtained to confirm an enhancement of the absorption efficiency in the favorable configuration. The results of the electromagnetic wavelength-scale analysis undertaken will have scientific and practical importance for optimizing the operation of thin-filmmulti-nanolayer PV structures incorporating a chirped DBR reflector with regards to enhancing their efficiency.

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Enhancement of Air-groundMatching by Means of a Chirped MultilayerStructure: Electromagnetic Modelingwith the Method of Single Expression

Baghdasaryan H., Knyazyan T., Hovhannisyan T., Marciniak M., Pajewski L.

Journal of Telecommunications and Information Technology

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2017

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nr 3

30--36

EN

The enhancement of air-ground electromagneticmatching by means of a chirped multilayer structure is inves-tigated. The modeling and simulation of the considered struc-ture are performed by using the method of single expression(MSE), which is a convenient and accurate tool for wavelength-scale simulations of multilayers comprising lossy, amplifyingor nonlinear (Kerr-type) materials. Numerical results showthat a suitable chirped multilayer structure can reduce the re- ection from the ground. Different values of the number oflayers and of the layer thicknesses are considered. The distributions of the electric eld components and the power owdensity within the modelled structures are calculated.

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Absorption loss influence on optical characteristics of multilayer distributed Bragg reflector : wavelength-scale analysis by the method of single expression

Baghdasaryan H. V., Knyazyan T. M., Baghdasaryan T. H., Witzigmann B., Roemer F.

Opto-Electronics Review

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2010

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Vol. 18, No. 4

438-445

EN

Electrodynamical model of a classical distributed Bragg reflector (DBR) consisting of alternating quarter-wave layers of high and low permittivity is considered at the plane wave normal incidence. Reflective characteristics of DBR possessing absorption loss in constituting layers are analysed via correct wavelength-scale boundary problem solution by the method of single expression (MSE). Analysis of optical field and power flow density distributions within the lossy DBR structures explained the peculiarities of their reflective characteristics. Optimal configurations of lossless and lossy DBRs are revealed. Specific DBR structures possessing full transparency at definite number of layers are also analysed.