It is highly desirable to discover sensing mechanisms for developing self-powered and ultrasensitive pressure sensing. Here, we report that the piezo-optoelectronic coupling in a n-3C-SiC/p-Si heterojunction not only enables energy harvesting but also features massive strain sensitivity. To demonstrate the proof of the concept, a pressure sensing device is developed with active and reference electrodes arranged on SiC along strain-sensitive [100] and strain-insensitive [110] orientations, respectively. Under the illumination of 637-nm laser at 2.0 mW, experimental results show the great response of the photogenerated voltage to the change in both static and dynamic pressures. Gauge factor is found to be −670.2 which is much larger than the highest gauge factor of n-type 3C-SiC. The underlying physics behind is the strain modulation on the effective mass and energy level of photogenerated charge carriers. This results in the change in carrier concentration detected by the electrodes along the strain-sensitive and strain-insensitive orientations. These findings could contribute significantly to the development of self-powered mechanical sensors using solid-state electronics.

中文翻译：

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用于自供电和超灵敏压力传感的异质结中的压电光电耦合

非常需要发现用于开发自供电和超灵敏压力传感的传感机制。在这里，我们报道了 n-3C-SiC/p-Si 异质结中的压电光电耦合不仅能够收集能量，而且还具有巨大的应变敏感性。为了证明这一概念，我们开发了一种压力传感装置，其有源电极和参考电极分别沿应变敏感 [100] 和应变不敏感 [110] 方向排列在 SiC 上。在2.0 mW的637 nm激光照射下，实验结果表明光生电压对静态和动态压力的变化都有很大的响应。应变系数被发现为-670.2，远大于n型3C-SiC的最高应变系数。背后的基本物理原理是对光生电荷载流子的有效质量和能级的应变调制。这导致电极沿应变敏感和应变不敏感方向检测到的载流子浓度发生变化。这些发现可能对使用固态电子器件的自供电机械传感器的开发做出重大贡献。