Ultrasensitive strain sensor enhanced by Bonded Light Emitting Diodes

Herein we report a strain sensor with SiC/Si heterostructure exhibiting performance enhanced toward ultra-sensitivity using a bonded pico-light-emitting-diode. First, a cantilever with SiC/Si heterostructure is fabricated, followed by bonding a pico-LED on the top of the cantilever. The lateral photovoltage and photocurrent, then, are investigated under different LED supply voltages. The lateral photovoltage and photocurrent are as high as 7.9 mV and 19.06 µA, respectively, as the bonded LED is powered by a supply voltage of 6V. Finally, the performance of the strain sensor was investigated. When the bonded LED is OFF, the gauge factor (GF) of the strain sensor is 20.5. This GF significantly increases to 18,000 when the bonded LED is ON, which is thousand-time modulation. In other word, the strain sensor with bonded LED has ultra-high sensitivity.