Organic-based materials for photonics and electronics
The Center for Organic Photonics and Electronics (COPE) was founded at the Georgia Institute of Technology in 2003 to foster research, education, and innovation in the field of organic photonics and electronics. The ability to produce lower-cost, flexible, wearable, and eco-friendly electronic applications – such as lighting, diagnostic devices, screens, and batteries – using various organic-based materials has great potential as the world moves toward greater sustainability in products, processes, and resources. COPE’s research ranges from materials theory and modeling to device design and fabrication.
• Organic materials and device architectures for future solid-state lighting and photovoltaics applications
• Nanocomposites for high energy-density storage applications
• Organic and hybrid thin-film transistors for flexible electronics applications
• Novel nanolithography techniques for the development of new electronics surfaces
• Barrier coatings for the packaging of organic and printed electronics
• Organic materials for all-optical switching and computing
Printed electronics offers a paradigm change in manufacturing, cost and environmental impact when compared to the conventional semiconductor industry. Printed electronic devices are expected to be mass-produced from less-energy-demanding roll-to-roll processes over large areas and on flexible substrates with techniques that closely resemble the well-known mass production of printed media on paper. Plastic electronics markets are expected to show strong growth in the next decade to reach a value of $80 billion by 2023.
This massive projected market growth offers a great economic opportunity but also introduces new challenges. Currently flexible plastic substrates continue to be considered the natural choice for developing printed electronic applications. Conventional flexible substrates suffer from some mechanical limitations, including some residual built-in stress that is introduced during the manufacturing process used to fabricate these films, for example extrusion.
To realize the full potential of organic printed electronics, new substrates based on multifunctional materials need to be developed. When considering the evolutionary trend of organic printed electronics it becomes apparent that the substrate platform is moving from being just flexible towards becoming increasingly conformal, stretchable, and soft. Substrates for printed electronics will also have to become more compatible with the human body. Ultimately, new material concepts will need to be explored to develop biocompatible devices for in-vivo electronics that can be implanted into the human body while minimizing biological rejection and inflammation.
Inorganic compound semiconductors
Wide bandgap semiconductors based on GaN and ternary alloys of AlGaN and InGaN are poised to play a critical role the future of electronics. Unlike Si, these materials can have bandgaps that are tunable with material composition over a range of 0.7 to 5 eV. This factor allows them to be used for optoelectronic devices that are the basis of the solid-state lighting revolution which is posed to save billions of dollars in reduced energy demand while lowering harmful greenhouse emissions, solar cells that provide alternative green energy sources and the development of UV light sources for water purification and biological detectors.
The high carrier mobilities and large breakdown fields in GaN-based semiconductors allow them to be used in advanced RF communication systems operating at high frequency (tens of GHz) and high power. These devices will be used in advanced radar systems as well as broadband telecommunications enabling video on demand and other culturally transformative technologies. Additionally, the high voltages these devices can operate under (tens of kV) make them suitable for use in power electronic modules necessary for hybrid and electric vehicles, solar photovoltaic inverters, power supply miniaturization and efficiency improvements and smart grid applications. Combined with solid-state lighting, GaN is poised to play a significant role in clean energy technologies involved with electrical energy generation or conservation in our nation’s future.
To achieve the goal of doubling America’s energy productivity by 2030, significant research still remains in the development of GaN electronics and the Georgia Institute of Technology is ready to play a leading role. Improvement in growth quality and doping of GaN is needed to improve the performance of optoelectronics for solid-state lighting. Since lattice matched growth substrates for GaN remain a challenge, the control of growth defects on lattice mismatched substrates and the resistance to heat dissipation must be addressed.
Researchers at the Georgia Institute of Technology are developing methods based on molecular beam epitaxy and metal organic chemical vapor deposition to create improved materials and doping methods. These technologies have recently shown increases in certain key figures of merit related to the ability to carry electricity of over 40 times what was previously considered a practical limit and have greatly lowered defect densities in these crucial materials using newly developed technologies from the Georgia Institute of Technology. Researchers are also developing advanced thermal management solutions involving new thermal interface materials based on nanotechnology and active cooling solutions embedded in the device to improve reliability and efficiency.
Georgia Tech also has leading expertise in the metrology of the temperature and stresses in GaN electronics to verify device performance and yield new insight into device reliability. The Georgia Institute of Technology is home of the National Electric Energy Testing and Research Applications Center which is focused on solving problems energy transmission and distribution for utilities which will benefit greatly from new power electronics for the smart grid.
Overall, Georgia Tech has a strong history of leadership in the field and collaborative work with industry and governmental agencies in the area of GaN electronics and is poised to continue to make groundbreaking contributions in the future.