Cool Innovation Alert! Room-Temperature Thermoelectric Devices Are Here!

organic thermoelectric device room temperature

New Organic Thermoelectric Device Harvests Energy at Room Temperature

A groundbreaking organic thermoelectric device has been engineered to operate at ambient temperature, negating the need for a temperature differential.

By employing distinctive organic compounds, this innovation has the potential to transform energy harvesting techniques by efficiently utilizing surrounding thermal conditions.

Researchers have introduced an organic thermoelectric device capable of capturing energy from the ambient environment. Despite the myriad applications of thermoelectric devices, challenges persist that inhibit their widespread deployment.

By integrating the unique properties of organic materials, the research team has crafted a framework for thermoelectric energy generation at room temperature without any required temperature gradient. Their findings were published in the esteemed journal Nature Communications on September 19.

organic thermoelectric device room temperature: Innovations in Thermoelectric Generators

Thermoelectric devices, commonly known as thermoelectric generators, consist of a collection of energy-converting materials that can transform heat into electricity, provided there exists a temperature gradient—where one end is heated while the other remains cool.

These devices have garnered considerable research interest for their potential to recover waste heat generated by various energy-producing processes.

Notably, thermoelectric generators find application in space exploration, such as in the Mars Curiosity rover and the Voyager spacecraft. These vehicles utilize radioisotope thermoelectric generators, which leverage the heat produced by radioactive isotopes to create the temperature gradient necessary for power generation.

Nonetheless, challenges such as exorbitant manufacturing costs, the use of hazardous materials, low energy conversion efficiency, and the requirement for elevated temperatures have limited the practical applications of thermoelectric devices.

Advances in Organic Thermoelectric Materials

Professor Chihaya Adachi from Kyushu University’s Center for Organic Photonics and Electronics Research (OPERA), who led the investigation, states, “We were exploring methods to create a thermoelectric device capable of harvesting energy from ambient temperatures.

Our lab emphasizes the functional applications of organic compounds, many of which exhibit exceptional properties for energy transfer.” He points to organic light-emitting diodes (OLEDs) and organic solar cells as prime examples of the efficacy of organic materials.

The research team focused on identifying compounds that serve effectively as charge transfer interfaces, facilitating efficient electron movement between materials. Through rigorous testing, they identified two promising candidates: copper phthalocyanine (CuPc) and copper hexadecafluoro phthalocyanine (F16CuPc).

“To enhance the thermoelectric properties of this novel interface, we also incorporated fullerenes and BCP,” Adachi elaborates. “These materials are recognized for their capabilities in facilitating electron transport.

The combination of these components significantly boosted the device’s performance, culminating in an optimized construct featuring a 180 nm layer of CuPc, 320 nm of F16CuPc, 20 nm of fullerene, and 20 nm of BCP.”

organic thermoelectric device room temperature: Outcomes and Future Directions

The finalized device achieved an open-circuit voltage of 384 mV, a short-circuit current density of 1.1 μA/cm², and a maximum output of 94 nW/cm²—all attained at room temperature without the necessity of a temperature gradient.

“Our advancements in thermoelectric device development position our new organic technology to propel the field forward,” concludes Adachi. “We aim to further refine this device using various materials and anticipate that increasing the surface area could yield higher current densities, an unexpected outcome even for organic materials. This illustrates the remarkable potential inherent in organic compounds.”

Reference

“Organic Thermoelectric Device Utilizing Charge Transfer Interface as the Charge Generation by Harvesting Thermal Energy” by Shun Kondo, Mana Kameyama, Kentaro Imaoka, Yoko Shimoi, Fabrice Mathevet, Takashi Fujihara, Hiroshi Goto, Hajime Nakanotani, Masayuki Yahiro, and Chihaya Adachi, 19 September 2024, Nature Communications. DOI: 10.1038/s41467-024-52047-5.