Comparative study of thin film n-i-p a-Si:H solar cells to investigate the effect of absorber layer thickness on the plasmonic enhancement using gold nanoparticles

Abstract

In this paper, the effect of gold nanoparticles on n-i-p a-Si:H solar cells with different intrinsic layer (i-layer) thicknesses has been studied. 100 nm and 500 nm i-layer based n-i-p a-Si:H solar cells were fabricated and colloidal gold (Au) nanoparticles dispersed in water-based solution were spin-coated on the top surface of the solar cells. The Au nanoparticles are of spherical shape and have 100 nm diameter. Electrical and quantum efficiency measurements were carried out and the results show an increase in short-circuit current density (J sc ), efficiency and external quantum efficiency (EQE) with the incorporation of the nanoparticles on both cells. J sc increases from 5.91 mA/cm 2 to 6.5 mA/cm 2 ($10% relative increase) and efficiency increases from 3.38% to 3.97% ($17.5% relative increase) for the 100 nm i-layer solar cell after plasmonic enhancement whereas J sc increases from 9.34 mA/cm 2 to 10.1 mA/cm 2 ($7.5% relative increase) and efficiency increases from 4.27% to 4.99% ($16.9% relative increase) for the 500 nm i-layer cell. The results show that plasmonic enhancement is more effective in 100 nm than 500 nm i-layer thickness for a-Si:H solar cells. Moreover, the results are discussed in terms of light absorption and electron hole pair generation.

Increased Absorption with Al Nanoparticle at Front Surface of Thin Film Silicon Solar Cell

“…Smaller nanoparticle results in higher parasitic absorption but gives a large peak at shorter wavelength and significant near-field enhancement. On the other hand, with larger nanoparticle high peak cannot be achieved compared to the smaller one but it provides a broad range stable scattering peak [30]. Therefore, to enhance the absorption within the Si absorber layer it is very crucial to choose the optimum size of nanoparticle and a reasonable trade-off is required for these two contradicting effects.…”

Light Scattering Calculations for Spherical Metallic Nanoparticles (Ag, Au) Coated by TCO (AZO, ITO, PEDOT:PSS) Shell

“…Therefore, the exploitation of LSPR of Ag and Au nanostructures is one of the key approaches to increase the optical absorption, by light trapping, in thin film Si solar cells, organic solar cells, and new-generation solar cells [ 1 , 2 , 3 , 4 , 5 , 13 , 14 ]. So, several schemes for functional devices incorporating plasmonic Ag and Au nanoparticles were recently proposed [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Generally, this can be achieved by the scattering of light, by the metal nanoparticles, at the cell’s interfaces, either by transmission at the top interfaces or by reflection at the rear ones [ 34 ].…”

“…For specific resulting performances, so, the system needs to be geometrically optimized to maximize scattering and minimize light absorption within the metal nanoparticles across the wavelength range of interest. In solar cell applications, the Ag or Au nanoparticles are usually supported on or embedded in a thin transparent conductive oxide (TCO) layer [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. TCOs are widely used as transparent electrodes for a variety of solar cell devices [ 35 ].…”

Full‐Spectrum Absorption Enhancement in a‐Si:H Thin‐Film Solar Cell with a Composite Light‐Trapping Structure

“…From the table, we can find that both open‐circuit voltage ( V oc ) and fill factor (FF) of a‐Si:H are comparable to other thin‐film solar cells, but the short‐circuit current density ( J sc ) is much smaller. Therefore, people have made much effort to enhance the light absorption of a‐Si:H thin‐film cells through various light‐trapping structures, which has proven to be very effective, [ 6 ] including deposition gratings [ 7-9 ] or antireflection coatings [ 10-12 ] on the front surface of solar cells, embedding plasmonic nanoparticles in different location of solar cells, [ 13-16 ] and deposing nanopatterns as the back reflector. [ 17-20 ] Although randomly textured surface is a commonly applied method to improve light absorption in conventional c‐Si, it is not a suitable way for thin‐film a‐Si:H cell due to the size restriction and increased surface recombination.…”