Power Generation on Chips: Harvesting Energy From the Sun and Cold Space

Environmental energy source is abundant, inexhaustible, ubiquitous, and free. However, harvesting thermal energy from the environment to generate uninterrupted electricity is still challenging. Herein, a power device to simultaneously harvest energy from the sun and cold space based on a microfabricated thermoelectric generator (TEG) integrated with a solar absorber (SA) and radiative cooling emitter (RCE) is reported. Nano-channel arrays structure is introduced in SA to achieve high broadband light absorption (≈96%) over the entire solar spectrum. Then, a typical RCE is fabricated to demonstrate the great potential of cooperating with SA to create a continuous temperature difference for thermal energy harvesting. Furthermore, a TEG sandwiched between SA and RCE can convert the thermal energy into electricity, which is proved by a chip-integrated micro-TEG experimentally. What is more, two self-generation power devices are designed, and the power generation of the reverse structure demo device (r-TEG) is 130% of the forward one (f-TEG) in the daytime and 260% in the nighttime. The results demonstrate a renewable and sustainable thermodynamic green resource on chips for power generation independent of time and geographical restrictions, which is vital for promoting the sun and cold space as viable energy sources beyond traditional technologies.