Viterbi Faculty of Electrical Engineering, Technion
Intersubband Gallium-Nitride Infrared optoelectronic devices on Si
We present for the first time an intersubband (ISB) infrared (IR) detector epitaxially grown on Silicon wafer. Integrated CMOS compatible IR detectors are very much desired, since they will revolutionize applications such as autonomous vehicles, defense and optical communications. At present, fabrication of IR detectors for imaging requires separated processes for the driving electronics and the detecting pixel's array, which augments the complexity and cost, and blocks wide adoption of IR sensing systems. Intersubband (ISB) detectors utilize optical excitation of electrons between confined states in quantum wells to detect light, usually in the IR spectrum. ISB detectors typically consist of several tens to hundreds of layers of III-V or II-VI materials, such as Gallium-Arsenide or Zinc-Cadmium-Selenide. Among III-V material systems, only the Gallium-Nitride (GaN) system is a mature and proven technology for epitaxial growth on Silicon and for standard compatible CMOS fabrication. The implementation of ISB detectors technology in the GaN material system is appealing for realization of ultra-fast integrated optoelectronic devices which can operate in a very wide spectral range, particularly in the optical communications band. Two GaN based types of ISB detectors are demonstrated and discussed- short wave IR (SWIR) photovoltaic quantum well infrared detector (PV-QWIP) grown on sapphire substrate and mid IR (MIR) quantum cascade detector (QCD) grown directly on silicon. The electrical and optical properties of the devices are compared to the expected values which were calculated using theoretical models and 8-band k.p solver. Performance analysis and modeling of the detectors are discussed along with plasmonic schemes for enhanced performance, which will accelerate the realization of integrated IR optoelectronic chip. * M.Sc. research under the supervision of Prof. Meir Orenstein and Gad Bahir.
Date: Mon 10 Dec 2018
Start Time: 14:30
1061 | Electrical Eng. Building