via Martin Luther University of Halle-Wittenberg
The photovoltaic effect of ferroelectric crystals can be increased by a factor of 1,000 if three different materials are arranged periodically in a lattice.
This has been revealed in a study by researchers at Martin Luther University Halle-Wittenberg (MLU). They achieved this by creating crystalline layers of barium titanate, strontium titanate and calcium titanate which they alternately placed on top of one another. Their findings, which could significantly increase the efficiency of solar cells, were published in the journal Science Advances.
Electric crystals do not require a so-called pn junction to create the photovoltaic effect, in other words, no positively and negatively doped layers. This makes it much easier to produce the solar panels.
However, pure barium titanate does not absorb much sunlight and consequently generates a comparatively low photocurrent. The latest research has shown that combining extremely thin layers of different materials significantly increases the solar energy yield. “The important thing here is that a ferroelectric material is alternated with a paraelectric material. Although the latter does not have separated charges, it can become ferroelectric under certain conditions, for example at low temperatures or when its chemical structure is slightly modified,” explains Bhatnagar.
Bhatnagar’s research group discovered that the photovoltaic effect is greatly enhanced if the ferroelectric layer alternates not only with one, but with two different paraelectric layers. Yeseul Yun, a PhD student at MLU and first author of the study, explains: “We embedded the barium titanate between strontium titanate and calcium titanate. This was achieved by vaporising the crystals with a high-power laser and redepositing them on carrier substrates. This produced a material made of 500 layers that is about 200 nanometres thick.”
When conducting the photoelectric measurements, the new material was irradiated with laser light. The result surprised even the research group: compared to pure barium titanate of a similar thickness, the current flow was up to 1,000 times stronger – and this despite the fact that the proportion of barium titanate as the main photoelectric component was reduced by almost two thirds. “The interaction between the lattice layers appears to lead to a much higher permittivity – in other words, the electrons are able to flow much more easily due to the excitation by the light photons,” explains Akash Bhatnagar. The measurements also showed that this effect is very robust: it remained nearly constant over a six-month period.
Further research must now be done to find out exactly what causes the outstanding photoelectric effect. Bhatnagar is confident that the potential demonstrated by the new concept can be used for practical applications in solar panels. “The layer structure shows a higher yield in all temperature ranges than pure ferroelectrics. The crystals are also significantly more durable and do not require special packaging.”
Original Article: Solar cells: Layer of three crystals produces a thousand times more power
More from: Martin Luther University of Halle-Wittenberg
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Solar cell efficiency
- Researchers demonstrate 25%-efficient perovskite-cadmium tandem solar cell
University of Toledo researchers say the cell has a top perovskite cell with a transparent back contact made of indium zinc oxide and a commercially established cadmium telluride bottom device. They ...
- Opinion: America's solar manufacturers need competition, not protection
Slapping tariffs on solar-cell imports is no way to bring back a domestic manufacturing base, writes the CEO of renewable developer Invenergy.
- U.S. scientists demonstrate 25%-efficient perovskite-cadmium tandem solar cell
The researchers say the cell has a top perovskite cell with a transparent back contact made of indium zinc oxide and a commercially established cadmium telluride bottom device. They claim the champion ...
- DOE invests $71 million in solar manufacturing R&D
The Dept. of Energy has announced more than $70 million in research and development selections to seed new technologies across the solar supply chain.
- Cadmium-doped perovskite solar cell achieves 22.7% efficiency
Canadian research group has utilized for the first time a cadmium iodide doping technique to stabilize the blade coating process in the manufacturing of solar cells based on formamidinium lead iodide ...
Go deeper with Google Headlines on:
Solar cell efficiency
[google_news title=”” keyword=”solar cell efficiency” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Ferroelectric crystals
- Crazy Crystals the Match 3 Game
Fox News is an independent company that does not claim any ownership of the term "Candy Crush". "Candy Crush" is only used for descriptive purposes and we do not claim any official association ...
- For Irresistible Energy On A Date, Try Wearing These 4 Crystals
This is where crystals come in. Think about whether you’d like to be powerful, alluring, or particularly calm, then look at your crystal collection, whether it’s rings, necklaces, or loose stones.
- Ferrodiode memory tested in 600 degree Celsius environment for 60 hours
The team said it took months of research to find what they described as the Goldilocks thickness for the metal / insulator / metal structures. The ...
- This new type of memory was demoed running at a scorching 600C for 60 hours
University of Pennsylvania researchers have demonstrated a new type of memory that runs at a melting 600C temperature, for over 60 hours.
- Towards novel promising perovskite-type ferroelectric materials: High-pressure synthesis of rubidium niobate
The material exhibits displacive-type ferroelectric behavior ... This study sheds light on the crystal structure and phase transitions across a broad temperature range (–268 to +800°C ...
Go deeper with Google Headlines on:
Ferroelectric crystals
[google_news title=”” keyword=”ferroelectric crystals” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]