Direct-Current Generator Based on Dynamic PN Junctions with the Designed Voltage Output

The static PN junction is the foundation of integrated circuits. Herein, we pioneer a high current density generation by mechanically moving N-type semiconductor over P-type semiconductor, named as the dynamic PN junction. The establishment and destruction of the depletion layer causes the redistribution and rebounding of diffusing carriers by the built-in field, similar to a capacitive charge/discharge process of PN junction capacitance during the movement. Through inserting dielectric layer at the interface of the dynamic PN junction, output voltage can be improved and designed numerically according to the energy level difference between the valence band of semiconductor and conduction band of dielectric layer. Especially, the dynamic MoS2/AlN/Si generator with open-circuit voltage of 5.1 V, short-circuit current density of 112.0 A/m2, power density of 130.0 W/m2, and power-conversion efficiency of 32.5% has been achieved, which can light up light-emitting diode timely and directly. This generator can continuously work for 1 h, demonstrating its great potential applications. [Display omitted] •High current density direct-current generator based on dynamic PN junctions•Dynamic equilibrium between establishment and destruction of the depletion layer•Capacitive discharge of PN junction capacitance caused by hot carriers rebounding•Enhance and design voltage numerically by inserting dielectric layer at the interface Electrical Engineering; Energy Materials; Mechanical Engineering; Tribology