A new technique could allow photoconversion to take place in the solid state, paving the way for crucial innovations in renewable energy, water purification and advanced healthcare.
Researchers at Exciton Science, based at UNSW Sydney, have shown that a key step in the photoconversion process can be carried out in the solid state, making the fabrication of a functional device on a commercial scale more likely. Possible applications include hydrogen catalysis and solar energy generation.
His work was published in the high impact magazine. ACS Energy Letters and is expected to lead to major changes in the approach of scientists around the world working in this difficult but potentially transformative area.
Professor Tim Schmidt of UNSW Sydney, principal investigator of Exciton Science and lead author of the paper, said: “I think people will immediately start copying us. I consider this a breakthrough because this approach can be adapted to ultraviolet or infrared photoconversion. There is a lot we can do with this. »
The photoconversion process
Photoconversion involves joining two low-energy photons to create more energetic visible light, which can be captured by solar cells or used for other purposes. The technical term for the joining process is “ triplet annihilation ”, which produces a “ exciton singlet ».
An exciton is a quasiparticle that exists when an electron and the hole to which it is attached are excited by light or another energy source. The controlled and reliable annihilation of triplets and the photoconversion it enables could increase the efficiency limit of solar energy devices from 33.7% to 40% or more.
Photoconversion research
Much of the basic research on photoconversion is carried out with liquid samples. For the mechanism to be useful in real-world device applications, it must be effectively demonstrated in solid state.
In this work, researcher Thilini Ishwara and her colleagues at Exciton Science created a thin film of nanostructured alumina dyed with a sensitizer.
The pores of the structure are filled with emitting molecules in concentrated solution, allowing a very promising photon generation quantum efficiency of 9.4% to be obtained.
Next steps for researchers
The next step for researchers is to go beyond the concentrated solution used in this approach and achieve similar results in a completely solid state, potentially using a gel-like substance.
“If you can make it small enough, you could use it to produce chemistry in the body”highlighted Thilini Ishwara.
“Higher energy light can be generated at a specific location within the body to treat tumors or create medications with laser precision. Water purification is another use of photoconversion. If you can convert the visible spectrum into sufficiently intense UV rays, you can kill germs and save millions of lives each year in developing countries. »
Other potential applications
Other applications potentially boosted by new photoconversion techniques include infrared technology, such as night vision, and even 3D printing.
Synthetic
Achieving solid-state photoconversion is getting closer to being a reality thanks to a new technique developed by Exciton Science researchers. This breakthrough could unlock major innovations in renewable energy, water purification and advanced healthcare. The possible applications are numerous and range from hydrogen catalysis to solar energy production, including night vision and 3D printing.
For a better understanding
1. What is photoconversion?
Photoconversion is a process of joining two low-energy photons to create more energetic visible light. This light can be captured by solar cells or used for other purposes, such as hydrogen catalysis or water purification.
2. What is an exciton?
An exciton is a quasiparticle that exists when an electron and the hole to which it is attached are excited by light or another energy source. The controlled and reliable annihilation of triplets and the photoconversion it enables could increase the efficiency limit of solar energy devices from 33.7% to 40% or more.
3. Why is it important to perform solid state photoconversion?
For the photoconversion mechanism to be useful in real-world device applications, it must be effectively demonstrated in the solid state. This makes it more likely to manufacture a device that works on a commercial scale.
4. What are the possible applications of photoconversion?
Potential applications include hydrogen catalysis, solar power generation, water purification, advanced healthcare, infrared technology (such as night vision), and 3D printing.
5. What’s next for researchers?
The next step for researchers is to go beyond the concentrated solution used in this approach and achieve similar results in a completely solid state, potentially using a gel-like substance.
Main caption illustration: Nanoporous alumina film colored with sensitizing molecules. Credit: Exciton Science
Article: “Sensitivity of Triplet Fusion Upconversion Nanoporous Solid State” – DOI: 10.1021/acsenergylett.3c01678
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