This fun group of scientists is the Lin Research Group at Georgia Institute of Technology. They work on a wide range of topics including solar energy since the group was created by Prof. Zhiqun Lin in 2011. The team is also called Nanostructured Functional Materials (NanoFM) research group, which should give you a clue about why they seem to be a fun group. Nano-technology is fun!
We strongly believe that nano-technology is the second renaissance. Thanks to the ability to work on materials a billionth smaller in size, scientists enjoy huge breakthroughs in their fields. Solar energy field is no exception.
The following projects are a sample of the solar energy related titles in the Lin Research Group’s website.
- Organic-Inorganic Nanocomposites by Placing Conjugated Polymers in Intimate Contact with Quantum Dots (Rods) and Their Use in Hybrid Solar Cells
- Dye- (and Quantum Dot)-Sensitized Solar Cells
- Low-Cost, High-Efficiency Solar Cells Based on Earth Abundant, Environmentally Friendly Copper Zinc Tin Sulfide (Cu2ZnSnS4) Nanocrystals
- Upconversion Nanocrystals: Synthesis, Self-Assembly and Applications in Solar Cells
Organic-Inorganic Nanocomposites by Placing Conjugated Polymers in Intimate Contact with Quantum Dots (Rods) and Their Use in Hybrid Solar Cells
One may argue that the nano-technology is not fun. However, we believe that nobody can deny how impressive the Quantum Dots are. These are nano particles that emit photons in different wave length (color) based on the particle size. This is a very distinct feature as other materials used in photovoltaics show the same features no matter what the particle size is.
The following picture demonstrates what happens when different size Quantum Dot particles are exposed to light. The smaller the Quantum Dot, the closer the wavelength (color) is to blue and the larger the Quantum Dot, the closer the wavelength (color) is to red. Based on the size, the wavelength can also be set beyond what’s visible to human eyes, i.e. infrared. Whether you are a high school student or a professor, this should be impressive.
Using Quantum Dots in photovoltaics is a relatively new and extremely promising approach. Simply put, by combining different size Quantum Dot particles, theoretically the whole spectrum of light can be absorbed, increasing the solar cell module efficiency significantly. With the materials currently used in solar energy field, like Crystalline Silicon, the energy band is fixed, thus, only a portion of light can be absorbed no matter what the particle size is. The Lin Research Group takes a step further and combines conjugated polymers with Quantum Dots. This results in a well-defined interface & much higher energy transfer between the two compared to cases where only Quantum Dots are used. Prof. Lin’s team is creating Conjugated Polymer Quantum Dot (CP-QD) nanocomposites and investigating their photophysical features as well as their use as organic-inorganic (Conjugated Polymer-Quantum Dots) in solar cells.
Before moving on to the next project, it is worth mentioning that the Lean Research Group works on Quantum Dots as well as Quantum Rods. The two are different in the way the particles are confined. The following picture explains the difference further.
Dye- (and Quantum Dot)-Sensitized Solar Cells
Even though it’s not as new as the use of Quantum Dots in solar cells, Dye Sensitized solar cells is a relatively new & promising concept. Both approaches are defined under the Emerging PV title as seen in the solar cell efficiency chart below. This graph is from National Renewable Energy Laboratory (NREL) and the most recent version can be seen by clicking on this link.
The average efficiency of Dye Sensitized Solar Cells (DSSC) is lower than the Crystalline Silicon that dominates the house-hold deployments but the cost associated with the DSSC is also much lower. Lin Research Group in this project utilizes nanotubes and nanoflowers as photoanodes to obtain high efficiency DSSCs.
Low-Cost, High-Efficiency Solar Cells Based on Earth Abundant, Environmentally Friendly Copper Zinc Tin Sulfide (Cu2ZnSnS4) Nanocrystals
One of the most important challenges in today’s solar energy field is the cost of materials (as well as the deployment of solar panels), even with the government incentives and tax credits. Due to space constraints, perhaps house-holds may not be able to enjoy the less efficient yet a lot less expensive Thin Film solar cells as opposed to Crystalline Silicone panels that dominate the retail market. Without the concern of space, large deployments of Thin Films provide a very promising alternative to Crystalline Silicone solar cells due to their much better cost effectiveness. However the most commonly used materials in thin film solar cells, CdTe and Cu2S, have toxic elements like Cd and expensive elements like indium (In).
We have covered the reason behind Indium price sky-rocketing in Salleo Group‘s review from Stanford University (click on this link to read the Salleo Group review). As a part of this project, by utilizing Copper Zinc Tin Sulfide (Cu2ZnSnS4; CZTS) nanocrystal-based solar cells, Lin Research Group is aiming for low-cost, environmentally friendly and high-efficiency solutions.
Upconversion Nanocrystals: Synthesis, Self-Assembly and Applications in Solar Cells
Yet again a new & promising concept that the Lin Research Group covers, upconversion nanocrystals. Salleo Group at Stanford University is also utilizing this technique.
The problem with the conventional solar cell designs is that the photons with lower energy than the band, the energy spectrum that results in electron movement / electrical current, are wasted without providing any benefit to the system. Upconversion is the technique where the photons with lower energy are absorbed and up-converted to energy levels that reside within the band. This way the lower energy photons will also be utilized, which may significantly improve the efficiency solar cells. The Lin Research Group utilize Upconversion Nanocrystals from this perspective to reach higher efficiency solar cells.
By now, you must have realized why the Lin Research Group is a fun team. These projects are all extremely exciting and they revolve around new/promising concepts. We have greatly enjoyed reviewing Lin Research Group’s projects and we will be following this team closely in the future.
For more information about the Lin Research Group projects, please visit the team’s website by clicking on this link.
Prof. Zhiqun Lin
Prof. Zhiqun Lin started his academic career with a B.S. degree in Materials Chemistry from Xiamen University in 1995 followed by an M.S. degree in Macromolecular Science from Fudan University in 1998. Later he went to University of Massachusetts at Amherst and earned his Ph.D. degree in Polymer Science & Engineering in 2002.
Before becoming an Associate Professor in the School of Materials Science and Engineering at the Georgia Institute of Technology in 2011, Prof. Lin was a faculty member in Iowa State University from 2004 to 2011. Prof. Lin made a great impression in Iowa State University especially with his work on self-assembling micro- and nanoscale structures (click on this link to read an article at Iowa State University website regarding Prof. Lin’s work on self-assembling micro- and nanoscale structures).
Besides his position as a faculty at Georgia Tech, Prof. Lin is also an Associate Editor in Journal of Materials Chemistry and a member of the Editorial Advisory Boards for the journal, Nanoscale.
Prof. Lin has over 150 published articles and he also authored a book. Click on the link below to visit Amazon.com page regarding Prof. Lin’s book.
Video clips that involve Prof. Lin are also available online:
This bright scientist, Prof. Lin, has earned many awards & honors throughout his career including:
- Invited participant at the National Academy of Engineering’s (NAE) 2010
- US Frontiers of Engineering Symposium, 2010
- ISU Award for Early Achievement in Research, 2010
- Young Engineering Faculty Research Award, College of Engineering at ISU, 2009
- NSF CAREER Award, 2009
- MSE Department Excellence in Teaching Award, 2007
- 3M Non-tenured Faculty Award, 2006
- Frank J. Padden Jr. Award in Polymer Physics, American Physical Society, 2002
- Excellent Graduate Student Award, Fudan University, 1997
- Excellent Undergraduate Student Thesis Award, Xiamen University, 1995
- Lu Jia-xi & Cai Qi-rui Award, Xiamen University, 1994
- Ben-dong Award, Xiamen University, 1993
- Cadacam Award, Xiamen University, 1992
One of the most impressive facts about Prof. Lin is his efforts to give back to the community. Since his work at Iowa State University, Prof. Lin has consistently contributed to the NanoFM website (click on this link to visit the website) to encourage high school students to step into the world of nano-technology.
To learn more about Prof. Zhiqun Lin, please visit the Lin Research Group website by clicking on this link.