Absorption In Silicon Solar Cells Research Articles

Theoretical insight into the enhancement of longer-wavelength light absorption in silicon solar cell with multilevel impurities

In this article, we theoretically demonstrate multilevel impurity photovoltaic effect in an efficient silicon dual-homojunction solar cell that ensures an extended absorption of longer wavelength light. Along with suitable contact work functions (Ni and Ta as anode and cathode, respectively), three impurity energy levels from acceptor type impurities (One from Tl and two from Zn) have been introduced in the energy gap of the absorber layer of the solar cell. The simulations have been performed with Solar Cell Capacitance Simulator (SCAPS-1D) program. The pristine Si solar cell shows a PCE of 25.4% with JSC = 37.99 mA/cm2, VOC = 0.780 V and FF = 85.76%. While the incorporation of Tl impurity level alone provides a PCE of 33.4%, with JSC = 51.56 mA/cm2, VOC = 0.789 V and FF = 82.03%, respectively. The PCE of the solar cell further enhances to 35.4% with an elevation of the short circuit current by 3.76 mA/cm2 due to the inclusion of Zn impurity into the optimized structure. This increment of the JSC and hence PCE is evolved from the longer wavelength light absorption due to impurity-assisted two-step photon upconversion in the solar cell.

Broadband antireflection Mie scatterers revisited-a solar cell and module analysis.

Reflectance, reduction, and light trapping enhancement are essential to maximize the absorption of silicon solar cells. The industrial state of the art method to improve the solar cell optics is wet chemical texturization of the front surface in combination with the deposition of antireflection coatings. This work analyzes an alternative route, namely a TiO2 pillar structure on the front side of a planar silicon solar cell encapsulated in ethylene vinyl acetate (EVA) and glass. It focuses on parameter variations of the structured TiO2 layer while taking the module encapsulation into account. It is shown that internal reflections at the front interface of the module play a crucial role for the structure design. This leads to optimized structures working in a different optical regime. While state of the art structures optimized for a half infinite encapsulation act as effective media, structures optimized for the full module show an improved performance by making use of diffractive effects. It could be shown that weighted reflectance of 4.7% can be reached for a solar module with TiO2 pillar structure on top of the silicon surface compared to 5.5% for a two-layer ARC with a TiO2 bottom layer and 2.3% for an isotexture, which is the state of the art structure for multicrystalline silicon cells.

Enhanced light absorption of silicon solar cells with dielectric nanostructured back reflector

This paper investigates the light absorption property of nanostructured dielectric reflectors in silicon thin film solar cells using numerical simulation. Flat thin film solar cell with ZnO nanostructured back reflector can produce comparable photocurrent to the control model with Ag nanostructured back reflector. Furthermore, when it is integrated with nano-pillar surface decoration, a photocurrent density of 29.5 mA/cm2 can be achieved, demonstrating a photocurrent enhancement of 5% as compared to the model with Ag nanostructured back reflector.

Enhanced absorption in silicon metamaterials waveguide structure

Metamaterial waveguide structures for silicon solar cells are a novel approach to antireflection coating structures that can be used for the achievement of high absorption in silicon solar cells. This paper investigates numerically the possibility of improving the performance of a planar waveguide silicon solar cell by incorporating a pair of silicon nitride/metamaterial layer between a semi-infinite glass cover layer and a semi-infinite silicon substrate layer. The optimized layer thicknesses of the pair are determined under the solar spectrum AM1.5 by the effective average reflectance method. The transmission and reflection coefficients are derived by the transfer matrix method for values of metamaterial’s refractive index in visible and near-infrared radiation. In addition, the absorption coefficient is examined for several angles of incidence of the transverse electric polarized (TE), transverse magnetic polarized (TM) and the total (TE&TM) guided waves. Numerical results provide an extremely high absorption. The absorptivity of the structure achieves greater than 98 %.

Design and optimization of Ag-dielectric core-shell nanostructures for silicon solar cells

Metal-dielectric core-shell nanostructures have been proposed as a light trapping scheme for enhancing the optical absorption of silicon solar cells. As a potential application of such enhanced effects, the scattering efficiencies of three core-shell structures (Ag@SiO2, Ag@TiO2, and Ag@ZrO2) are discussed using the Mie Scattering theory. For compatibility with experiment results, the core diameter and shell thickness are limited to 100 and 30 nm, respectively, and a weighted scattering efficiency is introduced to evaluate the scattering abilities of different nanoparticles under the solar spectrum AM 1.5. The simulated results indicate that the shell material and thickness are two key parameters affecting the weighted scattering efficiency. The SiO2 is found to be an unsuitable shell medium because of its low refractive index. However, using the high refractive index mediumTiO2 in Ag@TiO2 nanoparticles, only the thicker shell (30 nm) is more beneficial for light scattering. The ZrO2 is an intermediate refractive index material, so Ag@ZrO2 nanoparticles are the most effective core-shell nanostructures in these silicon solar cells applications.

Aluminum nanoparticles enhanced light absorption in silicon solar cell by surface plasmon resonance

In this paper, the surface plasmon resonance-enhanced optical absorption in thin silicon solar cells through aluminum sphere nanoparticles (NPs) was investigated. The effect of particle size and the distance between particles on absorption enhancement is studied using a finite-difference time-domain technique. The results showed that an enhancement of 40 % in absorption could be achieved by integrating the aluminum particles on thin silicon solar cells with the proper combination of NP parameters compared to those without aluminum particles. The work is useful for the further theoretical study and design for the plasmonic thin-film solar cell.