Enhancing the piezoresistive effect is crucial for improving the sensitivity of mechanical sensors. Herein, we report that the piezoresistive effect in a semiconductor heterojunction can be enormously enhanced via optoelectronic coupling. A lateral photovoltage, which is generated in the top material layer of a heterojunction under non-uniform illumination, can be coupled with an optimally tuned electric current to modulate the magnitude of the piezoresistive effect. We demonstrate a tuneable giant piezoresistive effect in a cubic silicon carbide/silicon heterojunction, resulting in an extraordinarily high gauge factor of approximately 58,000, which is the highest gauge factor reported for semiconductor-based mechanical sensors to date. This gauge factor is approximately 30,000 times greater than that of commercial metal strain gauges and more than 2,000 times greater than that of cubic silicon carbide. The phenomenon discovered can pave the way for the development of ultra-sensitive sensor technology.

增强压阻效应对于提高机械传感器的灵敏度至关重要。在本文中，我们报道可以通过光电耦合极大地增强半导体异质结中的压阻效应。在不均匀照射下在异质结的顶层材料层中产生的横向光电压可以与最佳调谐电流耦合，以调制压阻效应的大小。我们展示了立方碳化硅/硅异质结中可调谐的巨大压阻效应，从而产生了约58,000的超高应变系数，这是迄今为止报道的基于半导体的机械传感器的最高应变系数。该规格因子约为30，比商用金属应变仪大000倍，比立方碳化硅大2000倍以上。发现的现象可以为超灵敏传感器技术的发展铺平道路。