III-V compound semiconductor nanowires (NWs) have attracted significant attention as nanoscale light sources in integrated photonics due to their nanoscale size, good optical properties and strain relaxation feature enabling the monolithic growth on lattice mismatched substrates such as silicon. Single standing NW itself can act as a vertical cavity; and an array composed of few tens to thousands of NWs can also function as a lateral waveguide and cavity by forming a photonic crystal structure. Both configurations can be further designed to achieve high power light emitting diodes (LEDs) or lasers. By incorporating quantum structures such as quantum wells or quantum dots formed by different constituting materials, light emitting devices with different wavelengths can be achieved.
This project involves the design, growth, fabrication and characterisation of III-V compound semiconductor based quantum well nanowire light emitting devices with wavelength ranging from 1.3 to 1.6 μm for optical communication applications. Both experimental and simulation work will be performed to understand the structural, optical and electrical properties of both single and array nanowire devices. By investigating the fundamental light emission and extraction processes, resulting from the one-dimensional sub-wavelength nanowire geometry and spatially confined carrier injection, we aim to achieve high efficiency electrically injected nanowire light emitting devices as nanoscale light sources for numerous future applications.
Through this project, the student will develop skills in the area(s) of:
- Numerical simulation on light emission and extraction properties of nanowire light emitting devices
- Material growth, processing and device fabrication technologies within a cleanroom environment
- State-of-the-art nanofabrication techniques such as electron beam lithography and focussed ion beam processing
- Nanoscale optoelectronic material and device characterisation (structural, optical and electrical).