Solution-Processed Organic Ratchets for Energy Harvesting

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

The project is jointly funded by the Electronic and Photonic Materials (EPM) and the Polymers (POL) Programs, both in the Division of Materials Research (DMR), and by the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems (ECCS). Non-technical Description: Compact energy harvesters that collect energy from the environment and direct it to useful work can be advantageous in places where battery replacement is costly or not possible, for instance in sensors on bridges, in large chemical plants, or in electronic implants for the human body. The research team is working on a polymer-based device that is a key component of energy harvesters. This so-called "ratchet" device is capable of transforming electronic noise into stable direct current. The project addresses fundamental questions on the physics of organic semiconductors, organic chemistry, and material science. The project provides great opportunities to recruit and train undergraduate and graduate students with the involvement of more experienced post-doctoral researchers. The energy-harvesting theme is used to increase the awareness about energy waste and energy efficiency not only among the research community, but also among K-12 students via outreach programs. Young individuals are exposed to creative and innovative thinking about harvesting waste energy in smart appliances. Technical Description: There have been a number of attempts to create electronic ratchets. However, previously reported ratchets deliver low electrical current and voltage, have very complex fabrication procedure, and/or operate at cryogenic temperatures. The main goal of this project is to create a new electronic ratchet based on organic semiconductors that is simple to fabricate and able to achieve high power conversion efficiencies at room temperature. The research activity puts an emphasis on understanding the physical processes that govern the device operation in order to achieve higher performance and long-term stability. The team combines theory and computational models with materials synthesis, processing and electronic characterization such as scanning electrostatic force microscopy, scanning Kelvin probe microscopy, x-ray diffraction, electroabsorption, and radio-frequency engineering. The optimized ratchet device is tested within an actual energy harvester over a wide spectral range of electromagnetic radiation.