Charge Generation and Mobility in Perovskites Studied via Ultrafast Time-Resolved THz Spectroscopy

In a few years, the very promising performance of the perovskite materials for optoelectronic applications has exceeded that of all alternative technologies based on solution-processed materials. The strong promises steam from their rather intriguing physical properties; high absorption coefficients, long carrier diffusion lengths, small exciton binding energies and low electron−hole recombination rates. Despite the great promise, there are still some issues that limit large-scale requests of these materials. Practically, the focus of researchers is gradually shifting toward understanding the fundamentals of perovskites, as the intrinsic properties will define their performance in photonic applications.
The main goal of this project is to obtain accurate information on charge carrier dynamics in perovskite materials via time-resolved terahertz spectroscopy. This will be accomplished by the development of a time-domain spectrometer to provide direct access to both the absorption and refractive index spectra using THz radiation. Such a technique can detect and distinguish between the presence of bound (exciton or charge transfer states) and free charges with ultrafast time resolution. This method will expand our platform consisting of fs transient absorption and fluorescence up-conversion (for the investigation of electronic properties of excited states) to THz spectroscopy.