Tribo-Tunneling DC Generator with Carbon Aerogel/Silicon Multi-Nanocontacts

Although tip-enhanced tribo-tunneling in metal/semiconductor point nanocontact is capable of producing DC with high current density, scaling up the process for power harvesting for practical applications is challenging due to the complexity of tip array fabrication and insufficient voltage output. Here, it is demonstrated that mechanical contact between a carbon aerogel and silicon (SiO₂/Si) interface naturally forms multiple nanocontacts for tribo-tunneling current generation with an open-circuit voltage output (V_OC) reaching 2 V, and short-circuit DC current output (I_SC) of ≈15 µA. It has a theoretical current density (J*) on the order of 100 A m⁻². Molecular dynamics simulation and atomistic field theory show that a strong localized electronic excitation can be induced at a dynamic carbon/SiO₂ sliding interface, which is in good agreement with the experimental results. The DC power output is enhanced by the intense local pressure at the presence of nanocontacts, as well as the increased sliding velocity v. To demonstrate the method for practical applications, light-emitting diodes (LEDs) with different colors are successfully lighted by a single-carbon aerogel monolith/SiO₂ sliding unit, and the DC electricity is stored in a capacitor without an additional rectification circuit.