Semiconductors such as silicon and germanium absorb photons with energies greater than their bandgaps. For many applications, however, it would be desirable to achieve control over the absorption spectrum (absorption vs photon energy). We recently demonstrated this with silicon nanowires (Si NWs). Bulk silicon appears silver or grey, but we showed that vertical Si NWs take a range of colours, depending on their radii (Nano Letters 11, 1851 (2011)). We showed that arrays of Si NWs could be used as filters for colour and multispectral imaging (Applied Physics Letters 101, 193107 (2012) and Scientific Reports 3, 2460 (2013)). We incorporated p-i-n junctions into the NWs, and showed that they could be used as photodetectors for colour imaging (Nano Letters 14, 1804 (2014)). PhD projects are available on Si and Ge NW photodetectors for multispectral (visible to infared) imaging. These will be primarily experimental, but will also involve numerical modelling.
Leader: Kenneth Crozier
Sponsors: Australian Research Council
Electrical & Electronic Engineering
Convergence of engineering and IT with the life sciences