From Terahertz Spectroscopy to Novel Devices

Realising the potential of new materials in electronic devices requires a good understanding of their electrical properties. However, characterizing such materials can be challenging, particularly if the technology for making electrical contacts to them is yet to be developed. This is where non-contact probes of electrical conductivity come to the fore. In particular time-resolved terahertz photoconductivity spectroscopy (TRTPS) is an excellent free-space probe of the electronic properties of semiconductors that also allows charge-carrier dynamics to be followed with sub-picosecond time resolution.1 Thus, not only can the key figures-of-merit of a material be determined, but also parameters of charge formation and recombination.2