Refractive index sensing using a Si-based light source embedded in a fully integrated monolithic transceiver

This work proposes and demonstrates the concept of a complementary metal-oxide-semiconductor (CMOS)-compatible electrophotonic monolithic refractive index sensor in which a Si-based light source is directly integrated. The device consists of an embedded light emitter, a waveguide, a sensing area to place an analyte, and a photodetector. The behavior of the system was modeled and simulated using light propagation and semiconductor simulation software. Experimental devices were fabricated using all standard CMOS materials and procedures, and the tests showed changes in detected photocurrent related to the refractive index of the material in the sensing area, demonstrating the potential of the completely Si-based CMOS-compatible electrophotonic systems in the development of fully integrated sensors.