Organic Semiconductors: a Next-Generation Technology for a Greener Future#AboutBrilliantMatters
At Brilliant Matters, we want to contribute to a sustainable future where clean energy sources are accessible to all. We have focused all our efforts on creating organic semiconductors in a green, scalable way. One of the questions we get asked often is- so what do you do? What are organic semiconductors? What makes this technology green, and what is the impact? We thought that we would create a blog post focused on answering these important questions.
What is a semiconductor?
Let’s start from the beginning, perhaps one of the most important questions to make sense of what we do- what is a semiconductor?
Semiconductors are an important part of our daily life, they are in essentially every electronic device you use, cell phones, computers, cars, to name a few. These are just a few examples of where we use semiconductors in our daily lives yet, many of us do not know what a semiconductor is, and why it is an important component of these devices. To give a brief description – a semiconductor is a kind of material used to build electronic components, and is able to conduct electricity in response to certain stimuli (such as light), thus allowing for the creation of “on” and “off” states of electrical conductivity. They are really the heart of why these devices can function. Conventional semiconductors are typically made from materials such as silicon, and if you’ve ever opened a computer or cell phone, you’ve very likely laid eyes on these kinds of semiconductor materials.
What is an organic semiconductor?
So then, what is an organic semiconductor?
Organic semiconductors are quite different when compared with the typical silicon semiconductors you might see in your devices today. In fact, organic semiconductors are perhaps more closely related to the chlorophyll molecules found in a plant than they are to their conventional silicon counterparts. In the process of photosynthesis, light absorbing chlorophyll molecules capture the energy from sunlight and use this energy along with water and carbon dioxide to create oxygen and energy for the plant. In a similar fashion, organic semiconductors can be used to make a solar cell, where energy from sunlight is captured and converted into electrical energy using specialized organic semiconductor materials optimized for the job of light-energy harvesting.
Why should organic semiconductors be considered green?
And finally, why should organic semiconductors be considered a green technology, what is the impact?
Organic semiconductors are most often created using by-products from the fossil fuel industry (which might otherwise be burned if no better use was found for them). These petroleum industry by-products are then transformed using chemical reactions and used to create value-added products for various applications (e.g., solar cells). A common misconception is that because organic semiconductors are made using these petroleum industry by-products, they are not a green technology. When in fact, creating organic semiconductors useful in solar cells is one of the most environmentally friendly applications you could imagine for these by-products.
Using the power of chemistry, we can transform these by-products into specialty semiconducting plastics and dyes. These dyes can be dissolved and made into inks, and then printed to make electronic devices that have a wide variety of properties, from exhibiting different colours to having properties like stretchability or transparency. At their end of life, they can simply be recycled in a similar fashion to a plastic beverage bottle.
In contrast, a conventional semiconductor device made using silicon starts with mining the ore to obtain the raw silicon. It is then refined using energy intensive industrial processes to form materials that can be used to produce rigid electronic devices, such as computer chips or solar panels.
For silicon, at the end of life, these devices need to be carefully decommissioned, since the heavy metals used in their construction can be quite harmful for the environment if allowed to enter landfills. Rather than getting rid of these materials in a responsible manner, they are often shipped to developing countries and thrown into landfills. This electronic waste or “e-waste” issue is already massive problem right now, and is only expected to get worse in the next 20-30 years with the amount of growth we have seen in the adoption of solar energy. Although silicon solar panels are a type of clean energy source while in operation, and your cellphone is not actively polluting while in your pocket, the waste caused from these devices in the future is potentially harmful if not properly dealt with. Thus, organic solar cells have the potential to massively reduce the e-waste around the world by displacing incumbent technologies, which is a fundamental problem we are facing in the 21st century.
For a summary of this comparison, click here.