Jason Myers, USA finalist
Jason Myers is in the fourth year of his PhD in materials science and engineering at the University of Florida, USA. He has a Bachelors and Masters degrees in materials science and engineering from the same institution. His research focuses on the fundamental optical and electrical processes within photovoltaic devices, with an emphasis on organic materials.
Enhanced Organic Photovoltaic Cell Performance using Transparent Microlens Arrays
Organic-based photovoltaic (OPV) devices are a promising route to clean, renewable energy due to their processability and low source material cost compared to bulk silicon. However, their performance must be improved. Several improvement routes are under investigation, from optimisation of device architectures to novel materials synthesis.
My research focuses on another route: improved optical management. By more effectively using incoming light, it is possible to ameliorate the fundamental trade-off that exists between optical absorption and charge collection efficiency in OPVs. Since optical absorption lengths are typically greater than charge collection lengths, increasing the optical path length without altering charge collection efficiency increases absorption and device performance.
This lecture will present a soft lithography method to apply hemispherical microlens arrays to the light-incident surface of an OPV. With lens arrays, transmitted light is refracted due to the non-normal incident angle, giving it an increased path length through the active layers of the device. Reflection loss is reduced due to the nature of the lens arrays. When light is reflected, it can impact a neighbouring structure, where the spherical nature of the lens array gives it a large probability of being transmitted into the substrate and the active layers.
Devices with lens arrays show up to 30% improvement in short-circuit current and efficiency. The simplicity, near universal applicability and compatibility with high throughput manufacturing make this method attractive for further development.