Thin-film structures and devices for lasers and optoelectronics

The absorption and emission of light is fundamental to both optoelectronics and biological processes. This process usually takes place in discreet jumps, in which an excited state electron emits a photon as it returns to its ground state, or a photon is absorbed to create an excited state electron. Our growing ability to manipulate light and matter however now allows a different possibility, in which the photon and exciton are ‘mixed’ together, forming a type of state called a cavity-polariton. Rather than being of simple academic interest, cavity polaritons are a fascinating test-bed for fundamental physics and can have potential applications in ultra-low threshold lasers, on-chip communications elements and new types of quantum-mechanical simulator devices.

In this project, you will develop strong-coupled optical cavities that contain a range of organic materials, ranging from organic semiconductor thin films, perovskite nanocrystals and biological macromolecules. You will characterise their optical properties, including light harvesting capability and the ability to undergo optically-pumped lasing. One objective will be the fabrication of lasers that operate at very low pumping-thresholds. You will also develop nanoscale lithographic techniques to laterally pattern the cavity structures, forming optical micro- pillars, which you will explore with high-resolution microscopy techniques.

You will be based in the Electronic and Photonic Molecular Materials group in the University of Sheffield (http://www.epmm.group.shef.ac.uk/), and will access a wide range of experimental facilities at Sheffield and at out other partner universities in this project (Southampton and St Andrews). This is an experimental research project that will provide state-of-the-art training in device fabrication and optical spectroscopy, and is suitable for Physicists, Electronic Engineers or Physical Chemists who wish to build a career in the field of photonics and optoelectronics.