Controlled positioning of semiconductor nanowires using transfer printing techniques

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2022
Thesis identifier
  • T16241
Person Identifier (Local)
  • 201553976
Qualification Level
Qualification Name
Department, School or Faculty
  • The aim of this thesis work is to develop and investigate a deterministic integration approach based on the transfer-printing protocols for the integration of semiconductor nanowire devices onto non-native surfaces and into nanophotonic systems. The developed technique goes beyond the state of the art to demonstrate a semiconductor pick-and-place capability permitting successful and accurate operation at the nanoscale. In the first part of this thesis work, the controllable capture and release of target semiconductor nanowires onto host surfaces (e.g. Au, SiO2, Si, polymer) is presented; also arrays and patterns were created using selected nanowires as building blocks. Furthermore, a nanowire alignment method was developed allowing to control the position of single devices with high accuracy levels in the order of 200 nm. These developed protocols were used to assemble laterally aligned nanowire pairs with separations between individual elements as low as 1 µm. The developed transfer-printing technique was used for the assembly of photonic circuitry using nanowire lasers as the building blocks. Not only this was demonstrated in planar surfaces, but also on layered structures and in three dimensions, with a vertical separation in the order of few hundreds of nanometers. The unique laser properties of semiconductor nanowires were studied in large populations pre- and post-printing to understand the inter wire performance variation and the effects from the transfer-printing process. The majority of this thesis work was done using semiconductor nanowires fabricated in bulk (InP) or in core/shell (GaAs/AlGaAs) structures. The flexibility of the developed printing method however, is applicable to nanowires beyond those presented in this thesis. Finally, we have investigated possibilities of using laterally aligned nanowire pairs for the next generation of photonic devices. For systems with reduced separation (< 1 µm): a numerical model describing the high-frequency dynamics of evanescently-coupled nanowire lasers pairs was investigated. For the separation where no significant coupling was found (> 1 µm): a dual colour lasing emission system with course and fine separations between the individual wavelengths was shown. A significant part of this thesis work was focused on developing pick-and-place methods that allow integration of single nanowire devices and addressing challenges associated with this process. Thus, the aspiration behind this project was to develop a key-enabling technique that allows to capture a selected nanowire device and integrate it onto a target surface, with a positioning accuracy that is in the order of nanoscale dimensions of the device. The thesis work is concluded with the future directions of this project and shows preliminary results on the large-scale integration of nanowire devices and pick-and-place of quantum dot clusters.
Advisor / supervisor
  • Dawson, Martin
  • Hurtado, Antonio
Resource Type