The new type of solar panel has 500 layers of barium titanate, strontium titanate and calcium titanate and is 200 nanometers thick.
p>
The energy production of ferroelectric crystals in solar cells can be increased a thousand-fold thanks to an innovative arrangement of thin layers of materials, according to a statement from the Martin Luther Halle-Wittenberg University (MLU, Germany). MSN writes about this.
Researchers from MLU have discovered that alternating crystal layers of barium titanate, strontium titanate and calcium titanate can significantly increase the efficiency of solar panels.
Most solar cells are made of silicon — inexpensive and relatively effective material. However, scientists are constantly experimenting with new materials to increase the efficiency of photovoltaic cells. They recently tested ferroelectric crystals.
One of their advantages is that there is no need for a pn-junction, i.e. any positively and negatively doped layers, as in the case of silicon solar panels. However, pure barium titanate, the ferroelectric crystal tested by MLU researchers, absorbs little sunlight. It was decided to combine it with other substances to significantly increase the output of solar energy.
The materials were layered on top of each other, as it was very important that the ferroelectric alternated with the paraelectric. Although the latter does not have separated charges, it can become a ferroelectric under certain conditions, for example, at low temperatures or with a slight change in its chemical structure. The researchers placed a layer of barium titanate between strontium titanate and calcium titanate, vaporizing the crystals with a powerful laser and redepositing them on a carrier substrate. The resulting material consisted of 500 layers and was 200 nanometers thick.
The researchers found that their layered material provided a current 1,000 times stronger than that measured in pure barium titanate of equivalent thickness. The interaction between the layers led to a much higher dielectric constant — in other words, electrons can flow much more easily due to excitation by light photons, the scientists explained.
The team also showed that the measurements remained virtually constant over six months, meaning the material could be robust enough for commercial applications. Next, they will continue to investigate the exact cause of the photovoltaic effect in their layered material with a view to its possible implementation on a mass scale. Their work promises to be part of a potential revolution in the field of ferroelectric materials with possible applications in computer memory, capacitors and other electronic devices.