New Efficiency Records for Solar Cells Thanks to Indium

August 2022 | News

Photovoltaics and other renewable energies are essential elements on the way to climate neutrality, which Germany, for example, is aiming to achieve by 2045 and in the UK by 2050

Source: pixabay / andreas160578

The technology metal indium is helping to increase the energy production of solar modules. An efficiency of 50 percent could soon be reached.

The photovoltaic sector has so far been dominated by solar panels made of crystalline silicon, so-called thick-film modules. The amount of material needed in this process is high and is reflected in a significant weight. However, this is compensated for by efficiency of up to 22 percent. So far, other forms of solar modules have not been able to compete with this energy yield.

Thin-Film Modules on Their Way to More Efficient Power Generation Technology

While the energy optimum has been reached for thick-film modules, the maximum efficiency of another type of solar cell is far from being exhausted. The latest research results give rise to hopes of a significant increase in efficiency for so-called thin-film modules. So far, their energy yield is only about ten percent, leaving vast room for potential.

Besides amorphous silicon, the most important components of thin-film modules are various indium compounds, such as copper indium gallium diselenide (CIGS), which are only vapor-deposited. This makes the solar cells about a hundred times thinner than conventional silicon solar cells, reducing material usage and weight. The result is lower production costs, making them financially attractive for users. However, more installation space and modules are needed to achieve the same energy production as thick-film modules. Nevertheless, this is set to change.

Photovoltaics and other renewable energies are essential elements on the way to climate neutrality, which Germany, for example, is aiming to achieve by 2045 and in the UK by 2050

Source: pixabay / andreas160578

Thin-film modules are only a few micrometers thin and very flexible.

Thin-film modules are only a few micrometers thin and very flexible.
Source: iStock/laremenko

Efficiency Level of over 50 Percent Now Possible

Through continuous research in recent years, the efficiency factor of thin-film modules (CIGS) has been improved step by step. This is shown by these examples in which indium has contributed to the development of new photovoltaic technologies:

  • The Swiss Federal Laboratories for Materials Science and Technology increased the energy yield of solar moduls to 21.4 percent, according to a press release. The researchers combined several indium-based semiconductor materials to achieve this.
  • Scientists at the Fraunhofer Institute for Solar Energy Systems (ISE) succeeded in increasing the efficiency to 47.6 percent, as reported by the news portal Rawmaterials.net. This was again made possible by using various indium and gallium semiconductors, among others. By increasing the semiconductor spectrum, different wavelengths of sunlight can be used.
  • At the University of Wuppertal, the approach of combining organic and semi-organic semiconductor materials is being pursued, according to a research report. The latter are minerals of the perovskite group, which can be produced synthetically. A wafer-thin layer of indium oxide connects the two layers and thus reduces energy losses. Thus, an efficiency of 24 percent is achieved.

And science sees further room for increasing efficiency. As part of the“50 percent” project initiated by the German Federal Ministry of Economics, Fraunhofer ISE and others are continuing to work on optimizing solar cells. Research is being conducted in several directions, such as applying additional additives to the CIGS layer and optimizing the substrate material and the coating process.

Growing Demand for Indium Expected

Photovoltaics and other renewable energies are essential elements on the way to climate neutrality, which Germany, for example, is aiming to achieve by 2045 and in the UK by 2050. However, demand for solar systems is also being driven by the war in Ukraine and the subsequent sharp rise in energy prices. The continuously improved thin-film modules are also likely to benefit from the solar boom, and demand for indium is expected to rise.

Thin-film modules are only a few micrometers thin and very flexible.

Thin-film modules are only a few micrometers thin and very flexible.
Source: iStock/laremenko

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