Nonlinear Semiconductor-Metal Phase Transition Induced Frequency Modulation (FM) based Mid-Infrared Detection at Room Temperature

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PROJECT ABSTRACTProposal Title:Nonlinear Semiconductor-Metal Phase Transition Induced Frequency Modulation (FM) based Mid-Infrared Detection at Room Temperature(2015722)Non-technical AbstractThe proposed research intends to develop a novel infrared detection scheme that takes advantage of the ultrafast resistance change in self-resonant vanadium dioxide film at the semiconductor-metal transition. The optical antenna patterned composite film absorbs strongly across a wide incident angle effectively working like a light funnel. The phase transition and strong infrared absorption process results in large change in the resonance frequency. The proposed infrared detection scheme provides solutions to overcome limitations arising from thermal memory that has been a major bottleneck in operating vanadium dioxide-based detectors and promises much higher detectivity comparable to the cryogenically cooled detectors. The localized absorption and low thermal mass promise faster response compared to bulk absorption based present uncooled infrared detectors. The optical antenna pattern will be encoded in a master pattern. One such master produces 100’s of polymeric imprinting stamps, and one stamp can produce 1000’s of imprints without any noticeable pattern degradation for low cost uncooled infrared detection and imaging schemes. In this context, the proposed work is revolutionary because it promises uncooled, tunable and low-cost infrared detection. The program provides a good platform for interdisciplinary research and graduate education. The research will generate exciting scientific contents for enriching graduate and undergraduate teaching. The proposed project will also serve to train graduate students in nanolithography and optoelectronic device fabrication to prepare a qualified work force for US manufacturing industry.Technical AbstractA deterministic infrared absorption induced phase transition seems to be a plausible option for high-sensitive infrared detection at room temperature. This opens the opportunity to explore phase transition of vanadium dioxide in the context of this proposal where light localization on a nanostructured thin-film promises high-sensitive infrared detection. The optical antenna behaves as perfect light collector to couple light to the active vanadium dioxide film with ~100% efficiency where, in a unique way, the majority of the absorption takes place in the vanadium dioxide film instead of the gold optical antenna, required for high sensitive detection. This proposal will generate new scientific knowledge by (1) providing fundamental understanding of phase transition of nanostructured vanadium dioxide in presence of strong light localization, (2) the phase transition mechanism promising to create low-loss, long life-time plasmons on the interfaces of semiconductor-metal grains over a specified range of semiconductor-metal transition edge, resulting in high signal to noise ratio, (3) the detector time response measurements will shed light on the dominant phenomenon (Hubbard correlation or Peierls transition) of the phase transition of the nanostructured vanadium dioxide film, and (4) in the self-cascaded scenario, the central oscillation shifts over several kilo-hertz as the infrared radiation changes the local temperature. Tracking the change in the oscillator frequency with respect to change in local temperature, while the vanadium dioxide system is electrically biased in the phase transition edge promises higher sensitivity. All present detectors function based on amplitude modulation and the performance is limited by the amplitude noise. The proposed frequency modulation-based detection scheme offers noise resistance and higher photon detection sensitivity. Overall, frequency tunable high-sensitive infrared detection ability will add an unexplored dimension to room temperature infrared detection and imaging techniques.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.