What is light trapping in solar cell?

What is light trapping in solar cell?

Light trapping is the capturing of photons for use in applications such as solar cells, sensing, photo-electrochemistry, and thermal photovoltaics. Light enters the structures involved in these applications through refraction, scattering, or the systematic scattering provided by diffraction.

How does silicon absorb sunlight?

In a crystal, the bonds [between silicon atoms] are made of electrons that are shared between all of the atoms of the crystal. The light gets absorbed, and one of the electrons that’s in one of the bonds gets excited up to a higher energy level and can move around more freely than when it was bound.

What happens when sunlight falls on silicon?

Now, consider a photovoltaic cell made from a wafer-thin combination of p-type silicon laid over a layer of n-type silicon. When sunlight hits our cell, the energy of its photons excites electrons into states called ‘electron-hole pairs’.

How does the light trapping technique minimize optical losses in solar cell?

Using total internal reflection, light can be trapped inside the cell and make multiple passes through the cell, thus allowing even a thin solar cell to maintain a high optical path length.

How does a light trap work?

Today, most fly light traps employ ultraviolet light to attract insects and glue boards to trap and kill them. These types of traps are especially useful in commercial areas that may be negatively impacted by a large presence of flies, like restaurants, hospitals, and nursing homes.

How do solar panels turn sunlight into electricity?

When the sun shines onto a solar panel, energy from the sunlight is absorbed by the PV cells in the panel. This energy creates electrical charges that move in response to an internal electrical field in the cell, causing electricity to flow.

What happened to the sunlight in the solar cell?

When sunlight hits the semiconductor in the solar PV cell (step 1 in our high level review) the energy from the light, in the form of photons, is absorbed, knocking loose a number of electrons, which then drift freely in the cell.

How can optical losses be reduced?

How to Reduce Losses in Optical Fiber?

  1. Make sure to adapt the high-quality cables with same properties as much as possible.
  2. Choose qualified connectors as much as possible.
  3. Try to use the entire disc to configure (single disc more than 500 meters) in order to minimize the number of joints.

What is optical gain and loss?

Optical gain is the most important requirement for the realization of a semiconductor laser because it describes the optical amplification in the semiconductor material. This optical gain is due to stimulated emission associated with light emission created by recombination of electrons and holes.

What is meaning of light trap?

Definition of light trap 1 : a device that allows movement of a sliding part or passage of a person (as into a darkroom) but excludes light. 2 : a device for collecting or destroying insects that consists of a bright light in association with a trapping or killing medium.

Can we trap light?

You can’t trap light in a mirrored box, as there are no perfect mirrors (complicated dielectric mirrors can get to 99.999% reflectivity, but only for a very small region of the spectrum). On the other hand, it is possible to “trap” light by slowing it down. If you can stop the light, you’ve trapped it.

What is light trapping in solar cells?

Light trapping is usually achieved by changing the angle at which light travels in the solar cell by having it be incident on an angled surface.

How can we improve the light-trapping effect on microcrystalline silicon solar cells?

Improvement of light-trapping effect on microcrystalline silicon solar cells by using high haze transparent conductive oxide films. In: Proceedings of the 3rd World Conference on Photovoltaic Solar Energy Conversion, Osaka, Japan Kluth, O., Vetterl, O., Carius, R., Finger, F., Wieder, S., Rech, B., Wagner, H., 1999b.

How to choose the right light-trapping approach for a solar cell?

When choosing a certain light-trapping approach for a solar cell, several aspects should be taken into account such as the thickness of the cell, the bandwidth of the light that needs to be trapped, and the angle under which light needs to be accepted.

How do you do light scattering in a solar cell?

For amorphous or microcrystalline thin film silicon solar cells light scattering is usually achieved by nano-texturing the front TCO electrodes (with a typical root-mean-square surface roughness of 40–150 nm) and/or nano-textured back reflectors.