A High Current Density Direct‐Current Generator Based on a Moving van der Waals Schottky Diode

• Published in: Advanced materials (Weinheim) 2019-02, Vol.31 (7), p.e1804398-n/a
• Main Authors: Lin, Shisheng, Lu, Yanghua, Feng, Sirui, Hao, Zhenzhen, Yan, Yanfei
• Format: Article
• Language: English
• Subjects: Carrier mobility; Diodes; direct current; Electric contacts; Electric fields; Electrons; Energy conversion efficiency; Energy sources; generators; Graphene; graphene films; Heterostructures; Information industry; moving Schottky diodes; Nanogenerators; Organic light emitting diodes; Piezoelectricity; Schottky diodes
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201804398

Traditionally, Schottky diodes are used statically in the electronic information industry while dynamic or moving Schottky diode–based applications are rarely explored. Herein, a novel Schottky diode named “moving Schottky diode generator” is designed, which can convert mechanical energy into electrical energy by means of lateral movement between the graphene/metal film and semiconductor. The mechanism is based on the built‐in electric field separation of the diffusing carriers in moving Schottky diode. A current‐density output up of 40.0 A m−2 is achieved through minimizing the contact distance between metal and semiconductor, which is 100–1000 times higher than former piezoelectric and triboelectric nanogenerators. The power density and power conversion efficiency of the heterostructure‐based generator can reach 5.25 W m−2 and 20.8%, which can be further enhanced by Schottky junction interface design. Moreover, the graphene film/semiconductor moving Schottky diode–based generator behaves better flexibility and stability, which does not show obvious degradation after 10 000 times of running, indicating its great potential in the usage of portable energy source. This moving Schottky diode direct‐current generator can light up a blue light‐emitting diode and a flexible graphene wristband is demonstrated for wearable energy source. A sustainable dynamic or moving Schottky diode generator is designed, which can convert mechanical energy into electrical energy by means of lateral movement between the graphene/metal film and the semiconductor. The mechanism is based on the built‐in electric field separation of diffusing carriers in the moving Schottky depletion layer. This direct‐current generator with efficiency over 20% can light up a light‐emitting diode, and a flexible graphene wristband generator is demonstrated.