A photoelectric sensing chip for gas detection

 

Optical sensing technology has advantages including low delay, high precision, parallel operation and imaging, which has important applications in biomedicine, environment, agriculture and other fields. However, the current optical sensing technology usually relies on large-scale and complex spectral analyzing or imaging system, which limits its applications in on-site fast detection and light-load platforms. Moreover, due to the small refractive indexes and extinction coefficients of gases, gas detection is a technical challenge especially for the miniaturized optical sensing system. As is well known, the optical field manipulating and spectral engineering methods based on subwavelength optical resonance structures can significantly enhance the detection sensitivity and spectral analysis ability, which is also conducive for on-chip integration.

Photoelectric gas sensor based on on-chip photo-thermoelectric effect with
subwavelength structures

Professor Qin Chen’s group from Jinan University proposed a photoelectric gas sensor based on subwavelength optical resonance structures to enhance the photo-thermoelectric effect, which can realize optical sensing and spectral analysis functions with direct on-chip electrical signal output.

In this design, metal covered shallow etched gratings are used to construct a resonant absorption mode with strongly localized field distribution at surface and narrow linewidth, which is used for highly sensitive optical sensing. Vanadium oxide are adopted to convert the absorbed optical signal into an electrical signal, which is used for direct on-chip electrical signal output. Combined with the field enhancement of surface plasmon and the selective gas adsorption enhancement of metal organic framework materials (metal surface), the interaction between light and gas molecules in this system has been enhanced about 8000 times, and the detection of CO2 below 100 ppm can be realized on a single chip. Moreover, by arraying 80 sensors with different resonance wavelengths and combining with the deep learning compression sensing algorithm, the reconstructed spectrum with a resolution up to 0.01 nm is achieved in the mid infrared band. The research results provide a new technical approach for portable gas detection applications.

About The Group

Professor Qin Chen from the Institute of Nanophotonics of Jinan University is mainly engaged in the research of on-chip integrated optical sensing and detection, focusing on optical field manipulation to enhance sensitivity and on-chip microsystem integration for portable application. He has developed on-chip direct electrical readout broadband optical sensor, CMOS spectral analysis integrated chip, etc. He has published more than 70 research papers, authorized 3 US invention patents and more than 10 Chinese invention patents. Some of his achievements have been selected into the Top Ten Progress of Chinese Optics, and he has been awarded the National Excellent Doctoral Dissertation.

Article

Chen Q, Liang L, Zheng Q L, Zhang Y X, Wen L. On-chip readout plasmonic mid-IR gas sensor. Opto-Electron Adv 3, 190040 (2020).

DOI:10.29026/oea.2020.190040