Plasmonic solar cell

[7] Plasmonic-enhanced cells improve absorption by scattering light using metal nano-particles excited at their localized surface plasmon resonance.

The design for plasmonic-enhanced solar cells varies depending on the method being used to trap and scatter light across the surface and through the material.

[12] The concentrated near field intensity induced by localized surface plasmon of the metal nanoparticles will promote the optical absorption of semiconductors.

Recently, the plasmonic asymmetric modes of nanoparticles have found to favor the broadband optical absorption and promote the electrical properties of solar cells.

Despite these effects, the application of metal nanoparticles at the solar cells' front can bring considerable optical losses, chiefly due to partial shading and reflection of the impinging light.

Instead, their integration at the rear side of thin-film devices, particularly in between the absorber layer and the rear metallic contact (acting as reflective mirror), can circumvent such issues since the particles interact only with the longer-wavelength light that is weakly-absorbed by the cell, for which the plasmonic scattering effects can allow pronounced photocurrent gains.

[15] Such so-called plasmonic back reflector configuration has allowed the highest PV efficiency enhancements, for instance as demonstrated in thin-film silicon solar cells.

[12] The basic principles for the functioning of plasmonic-enhanced solar cells include scattering and absorption of light due to the deposition of metal nano-particles.

Metallic nano-particles can be used to couple and trap freely propagating plane waves into the semiconductor thin film layer.

In recent reported papers, the shape and size of the metal nano-particles are key factors to determine the incoupling efficiency.

[19] Nevertheless, in certain types of nanostructured solar cells, such as the emerging quantum-dot intermediate band solar cells, the highly intense scattered near-field produced in the vicinity of plasmonic nanoparticles may be exploited for local absorption amplification in the quantum dots that are embedded in a host semiconductor.

[20][21] Recently, the plasmonic asymmetric modes of nano particles have found to favor the broadband optical absorption and promote the electrical properties of solar cells.

In order for solar cells to be considered cost-effective, they need to provide energy for a smaller price than that of traditional power sources such as coal and gasoline.

Specific applications for rural communities would be water pumping systems, residential electric supply and street lights.

The solar cells could help to power high-consumption devices such as automobiles in order to reduce the amount of fossil fuels used.

Moreover, the noble metal nano-particles are impractical to use for large-scale solar cell manufacture due to their high cost and scarcity in the Earth's crust.

Al nanoparticles, with their surface plasmon resonances located in the UV region below the desired solar spectrum edge at 300 nm, can avoid the reduction and introduce extra enhancement in the shorter wavelength range.

[27][28] As discussed earlier, being able to concentrate and scatter light from the surface or the back side of the plasmonic-enhanced solar cell will help to increase efficiencies, particularly when employing thin photovoltaic materials.

[36] Recently, research at Sandia National Laboratories has discovered a photonic waveguide which collects light at a certain wavelength and traps it within the structure.

[38] Yue et al. used a type of new materials, called topological insulators, to increase the absorption of ultrathin a-Si solar cells.

Through integrating the nanocone arrays into a-Si thin film solar cells, up to 15% enhancement of light absorption was predicted in the ultraviolet and visible ranges.

With the use of common and safe materials, third generation solar cells should be able to be manufactured in mass quantities, further reducing the costs.

The losses due to this are not as effective because the differences in lattices allows for more optimal band gap material for the first two cells.

If a material has a large bandgap of phonons then the carriers will carry more of the heat to the contact and it won't be lost in the lattice structure.

Having unique features of tunable resonances and unprecedented near-field enhancement, plasmon is an enabling technique for light management.

[40][41] For boosting device performance, they conceived a general design rule, tailored to arbitrary electron to hole mobility ratio, to decide the transport paths of photocarriers.

The general design rule can be realized by spatially redistributing light absorption at the active layer of devices (with the plasmonic-electrical effect).

[40] Recently, the plasmonic asymmetric modes of nano particles have found to favor the broadband optical absorption and promote the electrical properties of solar cells.

[13][42] Reducing the silicon wafer thickness at a minimized efficiency loss represents a mainstream trend in increasing the cost-effectiveness of wafer-based solar cells.

These results demonstrate the feasibility and prospect of achieving high-efficiency ultra-thin silicon wafer cells with plasmonic light trapping.