News Article
Concocting a solution for low-cost electronics
USC chemists have created a solvent which is able to dissolve a series of nine semiconductors made from combinations of arsenic, antimony, bismuth, sulphur, selenium and tellurium. Applying this solution as a thin film to substrates like glass and silicon and evaporating the solvent leaves a high-quality film of crystalline semiconductor - perfect for use in electronics
Researchers at the University of Southern California have created a solvent that will dissolve semiconductors safely and cheaply, allowing them to be applied as a thin film that could create the next generation of low-cost electronics.
The technology already exists to “print” electronics using semiconductor “inks” at room temperature - a much cheaper process for making electronics than low-pressure vapour deposition.
The problem, until now, is that the only substance that could effectively dissolve semiconductors to form these inks was hydrazine - a highly toxic, explosive liquid used in rocket fuel.
Richard Brutchey and David Webber of the USC Dornsife College of Letters, Arts and Sciences mixed two compounds to create a solvent that effectively dissolves a class of semiconductors known as chalcogenides at room temperature.
“When the two compounds work together, they do something quite remarkable,” says Brutchey, a professor of chemistry at USC Dornsife.
Brutchey and Webber call the solvent an “alkahest,” after a hypothetical universal solvent that alchemists attempted to create to dissolve any and all substances. They’ve patented their alkahest, and presented their findings in the Journal of the American Chemical Society.
In the paper, they show how a mixture of 1,2-ethanedithiol (a colourless liquid that smells like rotten cabbage) and 1,2-ethylenediamine (a colourless liquid that smells like ammonia) is able to effectively dissolve a series of nine semiconductors made from combinations of arsenic, antimony, bismuth, sulphur, selenium and tellurium. These materials are often used in lasers, optics, and infrared detectors.
The solution was then applied as a thin film to substrates like glass and silicon and heated, evaporating the solvent and leaving only a high-quality film of crystalline semiconductor -perfect for use in electronics.
Image:On the left, bulk antimony triselenide (Sb2Se3) dissolved in the solvent mixture created by Webber and Brutchey, and on the right, a thin film of antimony triselenide derived from that solution using low-cost and low-energy input processing methods. Some day, this could be used for the low-cost processing of semiconductors for transistors, solar cells, LEDs and more. (Photo: Jannise Buckley)
“It’s inexpensive and easily scalable,” Brutchey says. “Our chemical understanding of the solvent system and how it works should allow us to expand it to the dissolution of a wide range of materials.”
The work has been described in detail in the paper, "Alkahest for V2VI3 Chalcogenides: Dissolution of Nine Bulk Semiconductors in a Diamine-Dithiol Solvent Mixture," by David H. Webber and Richard L. Brutchey, Journal of the American Chemical Society, 2013, 135 (42), pp 15722 - 15725. DOI: 10.1021/ja4084336
Funding for this research came from the National Science Foundation and USC Dornsife.
The technology already exists to “print” electronics using semiconductor “inks” at room temperature - a much cheaper process for making electronics than low-pressure vapour deposition.
The problem, until now, is that the only substance that could effectively dissolve semiconductors to form these inks was hydrazine - a highly toxic, explosive liquid used in rocket fuel.
Richard Brutchey and David Webber of the USC Dornsife College of Letters, Arts and Sciences mixed two compounds to create a solvent that effectively dissolves a class of semiconductors known as chalcogenides at room temperature.
“When the two compounds work together, they do something quite remarkable,” says Brutchey, a professor of chemistry at USC Dornsife.
Brutchey and Webber call the solvent an “alkahest,” after a hypothetical universal solvent that alchemists attempted to create to dissolve any and all substances. They’ve patented their alkahest, and presented their findings in the Journal of the American Chemical Society.
In the paper, they show how a mixture of 1,2-ethanedithiol (a colourless liquid that smells like rotten cabbage) and 1,2-ethylenediamine (a colourless liquid that smells like ammonia) is able to effectively dissolve a series of nine semiconductors made from combinations of arsenic, antimony, bismuth, sulphur, selenium and tellurium. These materials are often used in lasers, optics, and infrared detectors.
The solution was then applied as a thin film to substrates like glass and silicon and heated, evaporating the solvent and leaving only a high-quality film of crystalline semiconductor -perfect for use in electronics.
Image:On the left, bulk antimony triselenide (Sb2Se3) dissolved in the solvent mixture created by Webber and Brutchey, and on the right, a thin film of antimony triselenide derived from that solution using low-cost and low-energy input processing methods. Some day, this could be used for the low-cost processing of semiconductors for transistors, solar cells, LEDs and more. (Photo: Jannise Buckley)
“It’s inexpensive and easily scalable,” Brutchey says. “Our chemical understanding of the solvent system and how it works should allow us to expand it to the dissolution of a wide range of materials.”
The work has been described in detail in the paper, "Alkahest for V2VI3 Chalcogenides: Dissolution of Nine Bulk Semiconductors in a Diamine-Dithiol Solvent Mixture," by David H. Webber and Richard L. Brutchey, Journal of the American Chemical Society, 2013, 135 (42), pp 15722 - 15725. DOI: 10.1021/ja4084336
Funding for this research came from the National Science Foundation and USC Dornsife.
