Researchers from Florida State University and the FAMU-FSU College of Engineering have made strides in developing the solar cells of the future by investigating the performance of a next-generation material under real-world conditions. The study, published in The Journal of Physical Chemistry C, explores the use of perovskite, an alternative material to silicon in solar cell technology.
Perovskites have the unique ability to exhibit upconversion, wherein they absorb low-energy photons and convert them into high-energy photons through organic molecules. This upconversion phenomenon prompted the researchers to explore alternative ways of utilizing the unused photons that do not contribute to electricity generation.
The objective was to store the energy from one photon until another photon arrives, allowing the combination of the two photons into a single high-energy particle capable of overcoming energy barriers. By achieving this, one usable high-energy light particle could be emitted after the upconversion process.
Previous investigations into perovskites primarily focused on their degradation under high temperatures and intense light. However, this study aimed to examine the upconversion process in perovskite/organic bilayers under typical real-world conditions. Such understanding would guide researchers in optimizing these devices for commercial solar cell applications.
To conduct the experiment, the upconversion devices were subjected to a temperature of approximately 60 degrees Celsius using a heating element. Optical spectroscopy and X-ray crystallography were employed to analyze the devices’ properties.
The researchers discovered that the upconversion device’s performance significantly declined after exposure to high temperatures, not due to perovskite degradation, but rather because the organic molecules involved in the upconversion process crystallized under the heat, rendering the device ineffective.
While perovskite alone degrades when exposed to heat and light, the introduction of organic molecules prevents this degradation. The organic molecules contribute to a more durable perovskite material, offering promising prospects for the practical application of perovskite-based upconversion devices. However, further engineering advancements are necessary to address existing challenges.
The research conducted by the team contributes to the ongoing development of solar cell technology by identifying the impact of real-world conditions on the performance of perovskite-based devices.
Source: Florida State University