Both materials offer the potential for high efficiency PV devices and low production costs but are held back by a number of issues, chiefly instability under everyday conditions where the heat and moisture they would face causes quick degradation.
By combining the two in a hybrid structure, however, the Toronto researchers found the materials stabilized each other. The team created two devices, which are described in the paper Lattice anchoring stabilizes solution-processed semiconductors, published in the journal Nature.
One of the devices comprised a quantum dot structure with about 15% perovskites, primarily for use as a solar cell. The other was composed of perovskites with slightly less than 15% quantum dot materials and intended primarily for use as an LED.
The team reported the perovskite-rich material remained stable at 25 degrees Celsius and 30% humidity for six months. In the quantum dot device, the aggregation of nanoparticles – which commonly affects performance – was one fifth that seen in devices using the same material without perovskite.
The researchers now hope to see their results picked up by industry, and would like tests conducted to seek synergies between other similar materials. “Industrial researchers could experiment by using different chemical elements to form the perovskites or quantum dots,” said lead author of the paper Mengxia Liu, now a postdoctoral fellow at the University of Cambridge. “What we have shown is that this is a promising strategy for improving stability in these kinds of structures.”
Liu lauded the collaborative working environment that helped lead to the discovery, adding: “Perovskite and quantum dots have distinct physical structures and the similarities between these materials have been usually overlooked. This discovery shows what can happen when we combine ideas from different fields.”