Method for manufacturing core-shell coaxial gallium nitride (GaN) piezoelectric nanogenerator

A method for manufacturing a core-shell coaxial gallium nitride (GaN) piezoelectric nanogenerator based on wet etching, the core-shell coaxial gallium nitride piezoelectric nanogenerator comprising a core-shell coaxial gallium nitride nanowire array and a flexible substrate;

• a first conductive layer being provided on a surface of the flexible substrate;
• the core-shell coaxial gallium nitride nanowire array being fixed to the flexible substrate;
• a top end of the core-shell coaxial gallium nitride nanowire array being provided with a second conductive layer;
• the first conductive layer and the second conductive layer being connected to an external circuit via a wire;
• and a nanowire of the core-shell coaxial gallium nitride nanowire array being covered with an alumina layer;
• and the method comprising:
• covering a center part of a gallium nitride wafer with a mask;
• and providing a precious metal layer on a surface of the gallium nitride wafer;
• removing the mask from the gallium nitride wafer;
• and performing an electrodeless photoelectrochemical etching on the gallium nitride wafer to form a primary gallium nitride nanowire array on the center part of the gallium nitride wafer;
• removing the precious metal layer from the surface of the gallium nitride wafer;
• and depositing the alumina layer on the surface of the gallium nitride wafer by magnetron sputtering to cover the primary gallium nitride nanowire array to obtain the core-shell coaxial gallium nitride nanowire array;
• and
• providing the first conductive layer on the surface of the flexible substrate;
• and transferring the core-shell coaxial gallium nitride nanowire array to the flexible substrate;
• and
• providing the second conductive layer at the top end of the core-shell coaxial gallium nitride nanowire array;
• and connecting the second conductive layer with the external circuit through the wire to obtain the core-shell coaxial gallium nitride piezoelectric nanogenerator;
• wherein the first conductive layer is deposited on the flexible substrate by magnetron sputtering;
• the second conductive layer comprises a metal bonding layer and a gold layer;
• the metal bonding layer is deposited on the top end of the core-shell coaxial gallium nitride nanowire array by magnetron sputtering;
• and the gold layer is deposited on the metal bonding layer by magnetron sputtering.