Revolutionary Photoreceivers Based on Combining Si-MOS Process with SiGe Nanotechnology

In this effort, a new class of optoelectronic detector will be developed for the express purpose of sensitizing high-performance silicon CMOS receiver circuits to near infrared (NIR) signals in the 1310 and 1550 nm bands commonly used for optical communications. Our photosensitive polymer nanocomposite will consist of PbS colloidal quantum dots densely packed in a conjugated polymer matrix. The quantum dots will provide efficient NIR optical absorption and the semiconducting polymer, when combined with the quantum dots, will form a heterojunction, that allows waveguide photodetectors to be made directly on the receiver chips. Since integration of the photosensitive nanocomposite with the receiver chips will take place after they have already emerged from their CMOS process line, formation of the NIR detectors can be accomplished without raising any contamination or process compatibility issues. Our proposed research program includes synthesis and fundamental characterization of candidate blends with a view toward understanding how key optoelectronic properties such as refractive index, extinction coefficient, responsivity, and carrier mobility are related to the makeup and microstructure of the composites as controlled by their method of formation. Prototype CMOS-compatible NIR photoreceiver structures will be developed and characterized, and a demonstrate unit optimized for microwave photonics applications.