The concept of light-harvesting, self-powered mechanical sensors using a monolithic structure

Ninh

ACS Appl. Mater. Interfaces

et al. 2023

Self Cite

This paper presents a novel self-powered mechanical sensing based on the vertical piezo-optoelectronic coupling in a 3C-SiC/Si heterojunction. The vertical piezo-optoelectronic coupling refers to the change of photogenerated voltage across the 3C-SiC/Si heterojunction upon application of mechanical stress or strain. The effect is elucidated under different photoexcitation conditions and under varying tensile and compressive strains. Experimental results show that the relationship between the vertical photovoltage and applied strain is highly linear, increasing under the tensile strain while decreasing under the compressive strain. The highest sensitivities to tensile and compressive strains are 0.146 and 0.058 μV/ppm/μW, respectively, which are about 220 and 360 times larger than those of the lateral piezo-optoelectronic coupling reported in literatures. These extremely large changes in vertical photovoltages are explained by the alteration in effective mass, energy band shift, and repopulation of photogenerated holes in out-of-plane, in-plane longitudinal, and in-plane transverse directions when strains are exerted on the heterojunction. The significant enhancement of strain sensitivity will pave the way for development of ultrasensitive and selfpowered mechanical sensors based on the proposed vertical piezo-optoelectronic coupling.

Section: Resultssupporting

confidence: 44%

Section: Introductionmentioning

confidence: 99%

Vertical Piezo-Optoelectronic Coupling in a 3C-SiC/Si Heterostructure for Self-Powered and Highly Sensitive Mechanical Sensing

Ninh

ACS Appl. Mater. Interfaces

et al. 2023

Self Cite

“…Subsequently, they focused on improving the working temperature of the chip and conducted a series of related studies on chip electrodes. In recent years, Dzung Viet Dao et al [29][30][31] have been working on the application of SiC in MEMS sensors and have continued to fabricate and test piezoresistive pressure sensor chips based on P-type 4H-SiC. In summary, it is clear that the emergence of SiC and its application in high-temperature sensor devices may provide a better choice for sensor chip substrates.…”

Section: Microelectromechanicalmentioning

confidence: 99%

Exploring the nonlinear piezoresistive effect of 4H-SiC and developing MEMS pressure sensors for extreme environments

Fang

Qiang

et al. 2023

Microsyst Nanoeng

Microelectromechanical system (MEMS) pressure sensors based on silicon are widely used and offer the benefits of miniaturization and high precision. However, they cannot easily withstand high temperatures exceeding 150 °C because of intrinsic material limits. Herein, we proposed and executed a systematic and full-process study of SiC-based MEMS pressure sensors that operate stably from −50 to 300 °C. First, to explore the nonlinear piezoresistive effect, the temperature coefficient of resistance (TCR) values of 4H-SiC piezoresistors were obtained from −50 to 500 °C. A conductivity variation model based on scattering theory was established to reveal the nonlinear variation mechanism. Then, a piezoresistive pressure sensor based on 4H-SiC was designed and fabricated. The sensor shows good output sensitivity (3.38 mV/V/MPa), accuracy (0.56% FS) and low temperature coefficient of sensitivity (TCS) (−0.067% FS/°C) in the range of −50 to 300 °C. In addition, the survivability of the sensor chip in extreme environments was demonstrated by its anti-corrosion capability in H2SO4 and NaOH solutions and its radiation tolerance under 5 W X-rays. Accordingly, the sensor developed in this work has high potential to measure pressure in high-temperature and extreme environments such as are faced in geothermal energy extraction, deep well drilling, aeroengines and gas turbines.

“…Utilizing conventional sensors, which are powered by external power sources, in a sensor network is not realistic. In addition, powering many sensors using batteries creates major issues of system maintenance and environmentally unsustainable development. − Therefore, self-powered sensors without a need for batteries can be excellent solutions to these issues. In addition, the size of the sensing devices is significantly reduced as in most devices the battery size is much larger than the rest of the system.…”

Section: Introductionmentioning

confidence: 99%

Light-Harvesting Self-Powered Monolithic-Structure Temperature Sensing Based on 3C-SiC/Si Heterostructure

ACS Appl. Mater. Interfaces

Dinh

Bell

et al. 2022

Self Cite

Utilizing harvesting energy to power sensors has been becoming more critical in the current age of the Internet of Things. In this paper, we propose a novel technology using a monolithic 3C-SiC/Si heterostructure to harvest photon energy to power itself and simultaneously sense the surrounding temperature. The 3C-SiC/Si heterostructure converts photon energy into electrical energy, which is manifested as a lateral photovoltage across the top material layer of the heterostructure. Simultaneously, the lateral photovoltage varies with the surrounding temperature, and this photovoltage variation with temperature is used to monitor the temperature. We characterized the thermoresistive properties of the 3C-SiC/Si heterostructure, evaluated its energy conversion, and investigated its performance as a light-harvesting self-powered temperature sensor. The resistance of the heterostructure gradually drops with increasing temperature with a temperature coefficient of resistance (TCR) ranging from more than −3500 to approximately −8200 ppm/K. The generated lateral photovoltage is as high as 58.8 mV under 12 700 lx light illumination at 25 °C. The sensitivity of the sensor in the self-power mode is as high as 360 μV·K–1 and 330 μV·K–1 under illumination of 12 700 lx and 7400 lx lights, respectively. The sensor harvests photon energy to power itself and measure temperatures as high as 300 °C, which is impressive for semiconductor-based sensor. The proposed technology opens new avenues for energy harvesting self-powered temperature sensors.