Periodic Reporting for period 2 - OPTAGON (An optical approach to next generation refrigeration)
Reporting period: 2022-09-01 to 2024-02-29
According to fundamental thermodynamics, using light as a refrigerant could allow new cooling technologies providing an alternative for the presently prevailing mechanical compressor based heat pumps and their all-solid-state thermoelectric counterparts. Recent evidence shows that such a break-through is becoming possible with the right combination of the latest innovations in lighting, photovoltaics and nanotechnologies. Addressing the challenges of stopping the use of hydrocarbon and fluoride based refrigerants, and reducing the rapidly increasing global energy consumption on cooling and heating, OPTAGON aims to demonstrate and harness the fundamental phenomenon of electroluminescent cooling to develop the first thermophotonic coolers. This opens an entirely new way to tackle the challenges of efficient solid-state cooling, enabling cooling solutions potentially all the way from cryogenic coolers to domestic heat pumps. In a multidisciplinary cross-over approach we combine thin-film solar cell materials and light emitting diode structures with recently developed extremely efficient light extraction methods and emerging nanoengineering concepts using optical near-field effects to demonstrate the prospects of thermophotonics. This creates a fundamental and cutting-edge line of research, development, and innovation targeting a solid-state cooling revolution with a scientific underpinning, addressing the industrial needs for efficient cryogenic solid -state cooling. This project will combine synergies in theory, experiment and technology-development covering different fields from materials to photonics.
The second reporting period of the work has been marked by developing the building blocks needed to assemble full device prototypes for cooling and exploring the initial optimization tasks that are most likely needed to achieve sufficient performance. The first assembled devices have shown the expected general improvements in light extraction, but more detailed optimization is left to the final reporting period and will be decisive in assessing the near term potential of the technology.
Our results and progress suggest that we are progressing well towards being able to fabricate prototype devices combining efficient light extraction with high radiative luminescence efficiencies, required to observe electroluminescent cooling for the first time. This observation would mark a major milestone on the way to next generation optical cooling.