SBIR Phase I:Single broadband detector from visible to near infrared using the spin Seebeck effect

The broader impact of this SBIR Phase I project will provide the medical field with a broad response detector capable of pairing with cheaper disease diagnostic tools for improved healthcare.Currently, there is not a commercially available broadband detector that can capture visible light and near infrared light.The Phase I SBIR effort will lead to an advanced detector capable of spanning this light range and fulfilling this unmet need.As a commercial product, this detector can be used in multiple commercial sectors including unmanned vehicles, the medical field, and for the defense and security of the nation.For example, in the medical field the ideal light for tissue penetration is between visible and near infrared.The detector developed in this project would permit optical scans of human bodies for disease diagnosis.The optical scan will provide a cheaper and safer alternative in comparison to expensive MRI technology and high-energy sources, such as x-rays, that result in radiological exposure.The size of the global medical imaging market is currently valued at $16 billion and the proposed work would help healthcare services in rural areas have access to optical diagnosing services.Semiconductor-based detectors are limited to absorbing photons whose energy is equal to or slightly greater than the electronic band gap of the semiconductor.As a result, there is not a commercially available detector that can span 400-2200nm with fast detection.The expected outcome of this project is a single broadband detector, based off of the quantum spin Seebeck effect to generate a spin current, that can span 400-2200nm with a flat quantum efficiency and a high response time.The quantum efficiency (QE) of the patent-protected detector is almost three orders of magnitude lower than semiconductor-based detectors and the largest portion of the project is devoted to improving the QE to commercial levels.The project will accomplish the following goals: 1) prove the feasibility of increasing the quantum efficiency by two orders of magnitude, 2) make a readout circuit board, 3) show detector capabilities through building a benchtop-working prototype, and 4) design a compact prototype to be built during Phase II. As a commercial product, this detector can be used in unmanned vehicles, in the medical field, and for the defense and security of the nation.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.