3-D InGaAs/GaAs Helical Nanobelts for Optoelectronic Devices

This article systematically characterizes conductometric InGaAs/GaAs helical nanobelts for use with optoelectronic sensing. The responsiveness, energy conversion efficiency, and external quantum efficiency are improved compared to conventional sensors by reducing the length of 3-D helical nanobelts without losing exposure area. Nanorobotic assembly and characterization of 3-D helical in/out-of-plane nanobelt photodetectors allowed for stable intrinsic property characterizations. When compared to nanotube bundles, impovement in properties such as energy conversion efficiency, responsiveness, and external quantum efficiency are experimentally demonstrated in both an optical microscope and scanning electron microscope. A probe-type photodetector was assembled using nanorobotic manipulation and in-situ gold nanoparticle ink soldering. The highly efficient and sensitive 3-D InGaAs/GaAs helical nanobelt photodetectors enable many optoelectronic device applications such as being the probes for the near field optical microscopy, confocal microscopy, fluorescence microscopy, or spatial detection with further characterizations.