Organic solar cells Japanese researchers report a new method that could boost solar cell development
In the electronics industry, organic solar cells could be used for a range of valuable applications, particularly in the development of wearable devices. Now, scientists at Japan’s Okayama University have reported what they claim to be the first instance of an electrochemical reaction that produces thienoacenes, useful materials that are used in organic solar cells.
Organic photovoltaic (OPV) solar cells are the latest type of solar cell technology. They are highly strong absorbents of light and are capable of capturing and using much higher amounts of sunlight than other cells. This naturally makes them far more cost-effective and efficient when used in applications such as solar panels and potential future applications in electric vehicles and wearable devices.
Other advantages of OPV solar cells include the fact that they are very thin, lightweight, and can be used to cover large surface areas. Currently, they are a boon to the solar energy industry and are driving it forward as the latest OPV research and development continues to improve sustainability, one of today’s biggest challenges.
Combining the best properties: new material concept for solar cells
Using OPVs in electronics applications
One area where OPVs are expected to make a huge difference is electronics, particularly the development of new and novel electronic devices. This is because OPVs are ideal alternatives to common energy storage methods, such as lithium-ion batteries, and could help scientists and researchers meet their goals for developing greener, inexpensive, and portable energy sources.
As the rapid development of technology leads to increased demand from consumers and industry, the need to meet these goals will only grow more pressing. Often, the batteries in these devices are made from light and robust organic semiconductor molecules. However, synthesising these molecules involves using expensive rare metal catalysts in complex production process. This is what the Japanese team set out to change—and they claim to have done this with a new reaction system.
The Japanese team’s “novel” reaction system for thienoacene derivatives
Thienoacene derivatives are important components found in organic semiconductors. By using a system that makes use of environmentally friendly organic electrolysis, the team constructed carbon-sulphur (C-S) bonds because “they are… abundant and significant in the field of pharmaceuticals and materials science,” said Professor Seiji Suga. These bonds are typically constructed by a process known as transition metal-catalysed cross-coupling; this requires the use of expensive rare metal catalysts and drives up production costs.
Instead, the research team used a different eco-friendly process called “electrochemical carbon-heteroatom bond formation” which requires mild conditions and does not make use of expensive rare metal catalysts.
"Over the past several years, we were interested in the development of new methods for thienoacene synthesis, acene derivatives that have a good track record in organic electrochemistry, and are attractive candidates for useful organic materials,” added Professor Suga.
On the basis of their study and research, the team then found electrochemical methods for thienoacene synthesis. They found that the C-S bond formation took place in the presence of a bromide ion which acts as a catalyst for the reaction. Using this approach, the research team synthesised types of thienoacene derivatives called "π-expanded thienoacene derivatives.”