Renewable energy seems to be a huge talking point these days. Whether it’s solar energy, wind energy, theorised space lasers or tidal power, renewable energy is consistently being investigated to keep our planet’s emissions down and wildlife flourishing. Solar Energy is also now the cheapest form of energy surpassing fossil fuels.
Solar panels seem to be the most widely used and known of way to harness renewable energy. Ranging from small calculators to modern houses in sunnier climates, solar panels have been used to supplement our usual energy sources for many years and many more years to come.
JAPAN’S CORPORATION KANEKA’S BREAKTHROUGH
“The photoconversion efficiency is over 26% with a 180.4 cm2 designated area, which is an improvement of 2.7% relative to the previous record efficiency of 25.6%.” explains the authors in the study.
As of almost 2 years ago, commercial solar panels were approximately 21.5% efficient. Panasonic managed to make a solar panel that was 22.5% efficient. Considering the solar panels just sit still in sunshine to produce energy, this is plenty to help supplement an energy source.
“The cell was analysed to characterize lifetime, quantum efficiency, and series resistance, which are essential elements for conversion efficiency. Finally, a loss analysis pinpoints a path to approach the theoretical conversion efficiency limit of Si solar cells, 29.1%.”
THE TRICK THEY USED
For this specific study, the researchers were aiming to minimise band gaps – the energy range where no electron states can exist. By minimising the band gaps, less energy is needed to stimulate electrons.
Low resistance electrodes were placed towards the back end of the solar cells which increased the amount of photons that were collected from the front end of the cells. To protect the cell and to help collect photons more efficiently, each cell was coated with an anti-reflective layer and a layer of amorphous silicon.
A key aspect of this study is that it used “industrial applicable” processes, one of these being plasma-enhanced chemical vapour deposition (PECVD). This deposits the thin film from a gaseous state onto the substrate. This is usually carried out by a radio frequency or a DC discharge between two electrodes.
COMMERCIAL APPLICABILITY OF THE RESULTS
“Improving the photoconversion efficiency of silicon solar cells is crucial to further the deployment of renewable electricity,” the team from Japan’s Kaneko company explains in their statement.
By using processes that are industrially applicable, this means that the findings can be proactively used to make commercial solar panels that are of a higher efficiency than the currently marketed solar panels.
To conclude the study, the paper noted that “further work is required before the individual cells can be assembled into a commercially available solar panel.”
Considering that Japan’s New Energy was one of the funders of the study, it’s highly likely that it will be in everyone’s best interest for this study to be continued.
Panasonic were the previous holders of the record, so it wouldn’t be a surprise to see them try and reclaim this record.
The research has been published in Nature Energy.
WHAT IS A SOLAR PANEL?
Typically, your everyday solar panel will be made out of crystalline silicon. Specifically, the solar cells are made out of either polycrystalline silicon (composed of many smaller crystals known as crystallites) or monocrystalline silicon (homogeneous crystal framework containing no grain boundaries).
Thin-film modules are cheaper than the crystalline silicon method but also less efficient. This involves placing a thinly layered film of the solar cell onto a substrate of glass.
Solar cells are what’s known as photovoltaic. This just means that it can convert light into electrical energy. They’re connected to a rechargeable battery and in some cases, and inverter to convert the DC electricity to AC.
Because solar panels just sit on roofs, walls or whatever surface they’re mounted to, they’re an extremely clean energy source. By implementing more solar panels, less CO2 emitting energy sources are needed.
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