The industry has been dreaming of spray-on solar cell technology for a decade, and now IBM's Canadian R&D center -- an alliance of seven universities, including the University of Toronto, may have discovered it. The key to achieving spray-on solar technology. IBM researchers revealed that the secret component of spray-on solar cell technology is colloidal quantum dots.
Illlan Kramer, an IBM employee who is currently a postdoctoral researcher at the University of Toronto professor Ted Sargent, said: "Gummy quantum dots are semiconductor nanoparticles suspended in the liquid phase. They are very tiny and invisible to the naked eye, but can be seen in solution. It's black, just like ink. When you have materials like this, you can imagine how to deposit them on the film - by inkjet printing, slot extrusion coating or spraying Method.” He pointed out that the research team used the ink solution and the colloidal quantum dots of the spray droplet size to achieve the effect of almost drying while contacting the substrate.
Quantum dots are increasingly used in high-brightness LEDs and innovative window-built solar cells. IBM's Canadian R&D Center and the University of Toronto believe they are moving toward the use of quantum dots to achieve spray-on solar cell technology in this century. . Kramer called the newly developed process technology "SprayLD" because it uses atomic layer deposition (ALD) equipment; he said that the team has tried spraying technology on flat glass substrates, soft plastic substrates and hemispherical glass substrates, and using the above three Both substrates have successfully produced functional components.
Among them, the flat glass substrate is the most suitable simulation solution for mass production applications. As for the flexible substrate and the hemispherical substrate, it is necessary to consider manufacturability; Kramer said that if a flexible substrate is used, a reel like a printed newspaper can be considered. Process. As for the proof of concept through the hemispherical glass substrate, the research team envisioned that the solar cell material could be directly sprayed onto the surface of non-planar objects, such as aircraft wings or car fenders.
SprayLD technology can be directly applied to mass production on virtually any shape without any shape. Kramer's vision is to use a roll-to-roll process to create films that can be applied to a variety of surfaces, such as furniture on a balcony or aircraft wings, cars. Enclosures, etc. Next, researchers will further optimize the technology to increase efficiency. Kramer said that the research team's spray-on solar cells have achieved 8.1% energy conversion efficiency, and they are committed to raising the efficiency to 10% of the commercial threshold of commercial applications.
Kramer pointed out: "We are continuously improving the efficiency of energy conversion, and we are also trying to upgrade the process to support the production of larger-sized solar cells; it is expected that in 5 to 10 years, people will see solar cells using this technology in the market. IBM's Canadian R&D Center was established in 2012 with seven universities with a total investment of US$210 million (including IBM's investment of US$175 million).