Room Temperature Mid-IR Detection through Localized Surface Vibrational States of SnTe Nanocrystals
journal contributionposted on 26.09.2018, 00:00 by Matthew E. Cryer, Jonathan E. Halpert
Quantum dots (QDs) are now well established as promising materials for room temperature mid-infrared (MIR) detection beyond 3 μm. Here, we have replaced commonly reported mercury based quantum dots with less toxic SnTe and PbSnTe. Inverse MIR detection at room temperature is demonstrated with planar, solution, and air-processed PbSnTe and SnTe QD devices. The detection mechanism is shown to be mediated by an interaction between MIR radiation and the vibrational stretches of adsorbed hydroxyl species. Devices are shown to possess mA/W responsivity via a reduction in conductance due to MIR irradiation and, unlike classic MIR photoconductors, are unaffected by visible wavelengths. As such, these devices offer the possibility of MIR thermal imaging that has an intrinsic solution to the blinding caused by higher energy light sources.
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MIR radiationdevices offerSnTe QD devicesdetection mechanismhydroxyl speciesvibrational stretchesroom temperature mid-infraredenergy light sources3 μ mMIR irradiationInverse MIR detectionMIR photoconductorsquantum dotsair-processed PbSnTeroom Temperature Mid-IR DetectionSnTe Nanocrystals Quantum dotsroom temperatureLocalized Surface Vibrational States