Wyniki wyszukiwania - BazTech

1

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

|

2017

|

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.

2

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

|

2017

|

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.

3

Sensitivity of imaging properties of metal-dielectric layered flat lens to fabrication inaccuracies

Kotyński R., Baghdasaryan H., Stefaniuk T., Pastuszczak A., Marciniak M., Lavrinenko A., Panajotov K., Szoplik T.

Opto-Electronics Review

|

2010

|

Vol. 18, No. 4

446-457

EN

We characterize the sensitivity of imaging properties of a layered silver-TiO₂ flat lens to fabrication inaccuracies. The lens is designed for approximately diffraction-free imaging with subwavelength resolution at distances in the order of a wavelength. Its operation may be attributed to self-collimation with a secondary role of Fabry-Perot resonant transmission, even though the first order effective medium description of the structure is inaccurate. Super-resolution is maintained for a broad range of overall thicknesses and the total thickness of the multilayer is limited by absorption. The tolerance analysis indicates that the resolution and transmission efficiency are highly sensitive to small changes of layer thicknesses.