Nanoplasmonics and surface enhanced spectroscopy.

Simulation of plasmonic properties of Al nanoparticles on Si surface for dislocation luminescence intensity enhancement 
M.O. Kushlyk1,2, D.P. Slobodzyan2, R.M. Lys2, B.V. Pavlyk2
1Institute of Physics PAS, Al. Lotników 32/46, Warsaw 02-668, Poland 
2Department of Sensor and Semiconductor Electronics, Ivan Franko National University of Lviv, 79017, 107 Hen. Tarnavskoho Str., Lviv, Ukraine,
Е-mail: kushlykmarik@gmail.com 

Despite of numerous methods of improving silicon near infrared luminescence it’s efficiency remain to be very low. In our work [1] we demonstrate that combination of height-temperature treatment, doping of oxygen atoms and elastic deformation give us an increasing of luminescence energy efficiency up to 2.5%. In recent years, significant attention is paid to plasmonic effects of metal nanoparticles (NPs) formed in volume or on a surface of semiconductors. Especially interest have the effect of enhancement of luminescence emission intensity nearby metal NPs due to surface plasmon resonance (SPR).
To establish a possibility of luminescence enhancement we modulate a structure of Al-NPs randomly distributed on surface of Si samples. Simulation of the structures were made in a program Lumerical FDTD Solution, commercial software based on the FDTD method. This program used to calculate transmission and reflection spectra, distribution of electric fields near NPs and Purcell factor.
In this simulations we used Al-NPs with lenticular or cylindrical shapes and sizes from 400 up to 750 nm in diameters and 50 nm of thickness. During a studying of plasmonic properties of our structures a presence of SPR maximum near 1,4 µm wavelength in transmission and reflection spectra it is shown. Increasing of NPs diameter leads to shift of its positions toward lower energies. 
Simulation of electric field distribution and Purcell factor show us a height intensity resonance field in a middle between particles when the distance between them is in the range from 250 up to 400 nm. This fact in accompany with well matching of wavelength maximum of SPR resonance and dislocation luminescence in Si is quite promising for efficiency enhancement of our light emitting structures.

1.	D. P. Slobodzyan, M. O. Kushlyk, B. V. Pavlyk  Electroluminescence energy efficiency of Si-structures with different compound of nanoscale dislocation complexes // Applied Nanoscience. – 2018. – pp. 1–7. – DOI:10.1007/s13204-018-0729-5