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.<br/>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.<br/>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.