Chen Yunkang, Zhang Zhi, Wang Zhaozheng, Bu Tianzhao, Dong Sicheng, Wei Wenwang, Chen Zhiqiang, Lin Yuan, Lv Yi, Zhou Han, Sun Wenhong, Zhang Chi
Center on Nanoenergy Research, Research Center for Optoelectronic Materials and Devices,, School of Physical Science & Technology, Guangxi University, Nanning 530004 China.
CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P. R. China.
ACS Appl Mater Interfaces. 2022 May 16. doi: 10.1021/acsami.2c03853.
The semiconductor triboelectric nanogenerator (TENG) based on the tribovoltaic effect has the characteristics of direct current and high current density, but the energy transfer and conversion mechanism is not completely clear. Here, a series of gallium nitride (GaN)-based semiconductor direct-current TENGs (SDC-TENGs) are investigated for clarifying the carrier excitation and transport mechanism. During the friction process, the external output current always flows from GaN to silicon or aluminum, regardless of the direction of the built-in electric field, because of the semiconductor types. These results reveal that the carrier transport direction is dominated by the interfacial electric field formed by triboelectrification, which is also verified under different bias voltages. Moreover, the characteristics dependent on the frictional force have been systematically investigated under different normal forces and frictional modes. The open-circuit voltage and short-circuit current of SDC-TENG are both increased with a larger frictional force, which shows that the more severe friction results in both a larger interface electric field and more excited carriers. The maximum voltage can reach 25 V for lighting up a series of LEDs, which is enhanced by four times compared to the cutting-edge reported SDC-TENGs. This work has clarified the friction-dominated carrier excitation and transport mechanism for the tribovoltaic effect, which demonstrates the great potential of semiconductor materials for frictional energy recovery and utilization.
基于摩擦起电效应的半导体摩擦纳米发电机（TENG）具有直流和高电流密度的特点，但其能量转移和转换机制尚不完全清楚。在此，研究了一系列基于氮化镓（GaN）的半导体直流TENG（SDC-TENG），以阐明载流子激发和传输机制。在摩擦过程中，由于半导体类型，无论内置电场方向如何，外部输出电流总是从GaN流向硅或铝。这些结果表明，载流子传输方向由摩擦起电形成的界面电场主导，这在不同偏置电压下也得到了验证。此外，还系统研究了在不同法向力和摩擦模式下，SDC-TENG依赖于摩擦力的特性。SDC-TENG的开路电压和短路电流都随着摩擦力的增大而增加，这表明摩擦越剧烈，界面电场越大，激发的载流子越多。最大电压可达25 V，可点亮一系列发光二极管（LED），与前沿报道的SDC-TENG相比提高了四倍。这项工作阐明了摩擦起电效应中以摩擦为主导的载流子激发和传输机制，展示了半导体材料在摩擦能量回收和利用方面的巨大潜力。
