Nanogenerator (NG) based on ZnO: Synthesis, performance, and applications - Mini review

A nanogenerator (NG) is recently developed to harvest energy in a small scale. Nanogenerators' performance depends on piezoelectric and triboelectric effects for mechanical energy harvesting. Meanwhile, the pyroelectric and thermoelectric effects are also involved in thermal energy harvesting. ZnO as a semiconductor material has the potential material to be applied for nanogenerators. ZnO is a semiconductor material with n-type having a bandgap of 3.37 eV. Nanogenerators are naturally good portability, environmentally friendly, low cost, and easy to fabricate. The various synthesis methods such as hydrothermal, spin coating, and electrospinning show different results related to the performance of the nanogenerator (voltage and electric current). Moreover, nanogenerators can be applied to specific areas such as energy harvesting and sensing applications. Therefore, this paper will review the synthesis methods, performance, and applications of ZnO for nanogenerators.