University of Louisville
Single-Walled Carbon Nanotubes as Infrared Detectors and Transparent Electrodes
Institution
University of Louisville
Faculty Advisor/ Mentor
Gamini Sumanasekera
Abstract
Single-Walled Carbon Nanotubes (SWNTs) have displayed their use in a variety of applications. One such application is infrared (IR) sensing by fabricating a bolometric device. SWNTs were grown directly (via Chemical Vapor Deposition (CVD)) on a Silicon/Silicon Oxide substrate across a narrow trench. SWNTs were then exposed to IR radiation and the electrical response measured. Specifically, resistance was plotted against time as the infrared source was activated and deactivated. A change in resistance greater than 1% was measured in response to the activation of the LED. Another application of SWNTs was explored by growing (via CVD) SWNTs on a quartz substrate with the goal of creating a transparent electrode. Because the existing technologies’ electrical resistance is strongly affected by temperature, one measurement consisted of plotting resistance vs. temperature. As transparency is also important, the absorption of light was measured for a range of wavelengths. It was found that, metallic SWNTs resulted in a low resistance highly transparent (and yet still conductive) substrate where an increasing temperature resulted in increased resistance. Semi-conducting SWNTs resulted in a higher resistance substrate where the resistance actually decreased with an increasing temperature.
Single-Walled Carbon Nanotubes as Infrared Detectors and Transparent Electrodes
Single-Walled Carbon Nanotubes (SWNTs) have displayed their use in a variety of applications. One such application is infrared (IR) sensing by fabricating a bolometric device. SWNTs were grown directly (via Chemical Vapor Deposition (CVD)) on a Silicon/Silicon Oxide substrate across a narrow trench. SWNTs were then exposed to IR radiation and the electrical response measured. Specifically, resistance was plotted against time as the infrared source was activated and deactivated. A change in resistance greater than 1% was measured in response to the activation of the LED. Another application of SWNTs was explored by growing (via CVD) SWNTs on a quartz substrate with the goal of creating a transparent electrode. Because the existing technologies’ electrical resistance is strongly affected by temperature, one measurement consisted of plotting resistance vs. temperature. As transparency is also important, the absorption of light was measured for a range of wavelengths. It was found that, metallic SWNTs resulted in a low resistance highly transparent (and yet still conductive) substrate where an increasing temperature resulted in increased resistance. Semi-conducting SWNTs resulted in a higher resistance substrate where the resistance actually decreased with an increasing temperature.