Carrier Ultrafast Electrical Property Dynamics in Low Dimensional Perovskite Semiconductors

Low-dimensional semiconductors such as quantum dots and 2D layers can be solution-processed into thin-film electronic and optoelectronic devices. Due to their solution processing under low temperatures and non-vacuum conditions, they are vulnerable to defect states. As a result, they exhibit similar carrier transport properties to amorphous silicon, which is manifested by lower carrier mobility and shorter carrier drift lengths.
In this study, we utilize novel ultrafast photocurrent spectroscopy, with sub-20 picosecond time resolution, to capture the carrier transport dynamics prior to defect trapping. Traditional optical property characterization techniques, such as pump-probe transient absorption and time-resolved photoluminescence, are limited in their ability to understand carrier diffusion dynamics. Additionally, they present a significant gap between carrier dynamics and the performance of devices in operation.
We use ultrafast photocurrent spectroscopy to study the electrical property dynamics in low-dimensional materials, such as perovskite quantum dots and 2D layers. We address the most critical carrier drift and carrier-phonon scattering dynamics, which are highly dependent on the nanostructure of the low-dimensional perovskite and temperature.