Metal nanowire–polymer matrix hybrid layer for triboelectric nanogenerator

In this work, we studied the surface potential of a metal–polymer hybrid layer and its effect on the performance of a triboelectric nanogenerator (TENG). Ag nanowires (AgNWs) separately embedded in two different polymers–one with a positive tribopotential and the other with a negative tribopotential–were prepared as model hybrid systems. The surface potentials of the hybrid system were systematically investigated by Kelvin probe force microscopy. The results demonstrated that each component of the hybrid layer affected the other component because of the difference in their work functions. The following two important findings were obtained. First, the surface potential of each polymer shifted drastically toward that of Ag and the surface potential of Ag shifted toward that of each polymer. Second, higher density of AgNWs led to higher Ag-induced charge density in the polymer, which consequently resulted in larger shift in the surface potential of the polymer. TENG performance measurements revealed that the tribopotential difference between the contact surfaces of the AgNW–polymer hybrid layer and the perfluoroalkoxy alkane (or Nylon) used as the top triboelectric layer governed the TENG performance. Our systematic investigation of the surface potential of a hybrid surface consisting of two materials with different surface potentials provides insight into the design of triboelectric layers for high-performance TENGs.