14-02-2017 | | By Paul Whytock
Flexible solar cells that are more flexible than silicon-based products will create a diversity of design opportunities when it comes to portable and wearable technology. This makes organometal halide perovskite solar cells particularly attractive to design engineers because thanks to a low temperature manufacturing process these cells can handle applications where flexibility is demanded.
Recent work in this field at the Florida A&M University-Florida State University (FAMU-FSU) is particularly interesting and Professor Shangchao Lin is suggesting that organometal halide perovskites could be more mechanically flexible than silicon and other inorganic materials used for solar cells. They may also provide greater energy efficiency levels.
These cells have evolved in the two key areas of efficiency and stability and power conversion efficiency is now at a level of 20%, although one of the operating characteristics that has always raised concerns is stability. This problem has been reduced thanks to the use of different materials and device architectures. Of major significance has been the work on hole conductor free mesoporous devices.
In separate mathematical simulation driven studies Professor Lin found that organic-inorganic hybrid perovskites should be extremely malleable and flexible and whereas there has been much research into perovskites for energy related technologies there has always been reservations regarding whether they would be suitable for certain applications because of their crystal structure. The concern being that they would be prone to shattering thereby making them very unsuitable for use in solar panels.
However, Professor Lin has found hybrid perovskites are expected to fracture slowly through a crystalline-to-amorphous transition. This would make them more durable and damage tolerant to the extent it is possible they may absorb twice as much elastic energy from external loading than currently used materials in electronic devices like silicon and gallium arsenide.
Professor Lin and his team have also stated that hybrid perovskites possess very low thermal conductivity due to their organic component. The suggestion is that hybrid perovskites are twice as efficient as the current state-of-art thermoelectric material, bismuth telluride, which is expensive and composed of rare-earth elements.
This could make them a suitable technology for high efficiency thermoelectric energy conversion in a wide variety of flexible applications.