Md Foisal AR, Qamar A, Phan HP, Dinh T, Tuan KN, Tanner P, Streed EW, Dao DV. Pushing the Limits of Piezoresistive Effect by Optomechanical Coupling in 3C-SiC/Si Heterostructure.
ACS Appl Mater Interfaces 2017;
9:39921-39925. [PMID:
29098850 DOI:
10.1021/acsami.7b12128]
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Abstract
This letter reports a giant opto-piezoresistive effect in p-3C-SiC/p-Si heterostructure under visible-light illumination. The p-3C-SiC/p-Si heterostructure has been fabricated by growing a 390 nm p-type 3C-SiC on a p-type Si substrate using the low pressure chemical vapor deposition (LPCVD) technique. The gauge factor of the heterostructure was found to be 28 under a dark condition; however, it significantly increased to about -455 under illumination of 635 nm wavelength at 3.0 mW/cm2. This gauge factor is over 200 times higher than that of commercial metal strain gauge, 16 times higher than that of 3C-SiC thinfilm, and approximately 5 times larger than that of bulk Si. This enhancement of the gauge factor was attributed to the opto-mechanical coupling effect in p-3C-SiC/p-Si heterostructure. The opto-mechanical coupling effect is the amplified effect of the photoconductivity enhancement and strain-induced band structure modification in the p-type Si substrate. These findings enable extremely high sensitive and robust mechanical sensors, as well as optical sensors at low cost, as no complicated nanofabrication process is required.
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