Direct Current Piezoelectric Energy Harvesting Based on Plasmon‐Enhanced Solar Radiation Pressure

A piezoelectric energy generating device that produces electricity using plasmon‐enhanced solar radiation pressure (SRP) is developed. The SRP is greatly enhanced on the operational region of the device with a unique crater‐like structure, and direct current is generated successfully on the device. By optimizing the material and thickness of top electrode, a maximum power density of 396 µW cm−2 is obtained. In addition, by using Raman measurements, finite‐difference time‐domain simulation, and COMSOL Multiphysics analysis, it is confirmed that the SRP is greatly amplified on the operational region with the nanoscale surface roughness due to resonance between the incident light and surface plasmons. By increasing the rotational speed of an optical chopper used to measure the change in the output characteristics of the device, and comparing this with the simulated result, it is found that the constant charge produced by the piezoelectric effect arose due to the superposition of charge phases in the device. The solar light pressure is amplified and applied to a piezoelectric material to obtain an average current of 2.86 µA and a voltage of 242 mV. The name of the device is light pressure electric generator. The device is made into a crater structure by etching the GaAs wafer, and subsequently lead zirconate titanate and metals are deposited. Among metals, the optimal film thickness is when Ag is 60 nm.