The Route to Nanoscale Terahertz Technology: Nanowire-based Terahertz Detectors and Terahertz Modulators
Institute of Electrical and Electronics Engineers (IEEE) 00 (2018) 1-2
Large-Scale Statistics for Threshold Optimization of Optically Pumped Nanowire Lasers.
Nano letters 17:8 (2017) 4860-4865
Abstract:
Single nanowire lasers based on bottom-up III-V materials have been shown to exhibit room-temperature near-infrared lasing, making them highly promising for use as nanoscale, silicon-integrable, and coherent light sources. While lasing behavior is reproducible, small variations in growth conditions across a substrate arising from the use of bottom-up growth techniques can introduce interwire disorder, either through geometric or material inhomogeneity. Nanolasers critically depend on both high material quality and tight dimensional tolerances, and as such, lasing threshold is both sensitive to and a sensitive probe of such inhomogeneity. We present an all-optical characterization technique coupled to statistical analysis to correlate geometrical and material parameters with lasing threshold. For these multiple-quantum-well nanolasers, it is found that low threshold is closely linked to longer lasing wavelength caused by losses in the core, providing a route to optimized future low-threshold devices. A best-in-group room temperature lasing threshold of ∼43 μJ cm-2 under pulsed excitation was found, and overall device yields in excess of 50% are measured, demonstrating a promising future for the nanolaser architecture.Broadband Single-Nanowire Photoconductive Terahertz Detectors
2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) (2017)
Single n+-i-n+ InP Nanowires for Highly Sensitive Terahertz Detection
Nanotechnology IOP Publishing Ltd 28 (2017) 125202
Abstract:
Developing single-nanowire terahertz (THz) electronics and employing them as sub-wavelength components for highly-integrated THz time-domain spectroscopy (THz-TDS) applications are a promising approach to achieve future low-cost, highly integrable and high-resolution THz tools, which are desirable in many areas spanning from security, industry, environmental monitoring and medical diagnostics to fundamental science. In this work, we present the design and growth of n+-i-n+ InP nanowires. The axial doping profile of the n+-i-n+ InP nanowires has been calibrated and characterized using combined optical and electrical approaches to achieve nanowire devices with low contact resistances, on which the highly-sensitive InP single-nanowire photoconductive THz detectors have been demonstrated. While the n+-i-n+ InP nanowire detector has a only pA-level response current, it has a 2.5 times improved signal-to-noise ratio compared with the undoped InP nanowire detector and is comparable to traditional bulk THz detectors. This performance indicates a promising path to nanowire-based THz electronics for future commercial applications.Efficiency enhancement of axial junction InP single nanowire solar cells by dielectric coating
Nano Energy Elsevier 28 (2016) 106-114