Piezoelectric nanogenerators with high performance against harsh conditions based on tunable N doped 4H-SiC nanowire arrays

Piezoelectric nanogenerators (PENGs) have been attracting much attention for their high flexibility, low density and outstanding chemical stability in applications of environmental energy harvesting and self-powered sensors. Here, PENGs based on large scale free-standing N doped 4H-SiC nanowire arrays (NWAs) fabricated by anodic oxidation of single-crystalline N doped 4H-SiC wafer are proposed for the first time. Due to N-dopants bring the SiC semiconductors an enhanced piezoelectric performance, the as-prepared PENGs show excellent performance with the peak values of open circuit voltage and short circuit current density of 3.0 V and 200 nA cm−2, respectively. Service stability of PENGs has been proven by 20,000 consecutive charge-discharge cycles as well. Moreover, the PENGs exhibit high thermal stability against 200 °C and excellent acid-base resistance. The energy generated by PENGs is enough to charge capacitors through a full bridge rectifier without any external power supply, certifying that they can work as standalone nanoscale energy sources. These results innovatively expand the feasibility of 4H-SiC for application in a wide variety of high-performance energy harvesting devices.