Ultrafast Carrier Drift Transport Dynamics in CsPbI3 Perovskite Nanocrystalline Thin Films

We study the early time carrier drift dynamics in CsPbI3 nanocrystal thin films with a sub 25 ps time resolution.Prior totrapping, carriers exhibit band-like transport characteristics, whichis similar to those of traditional semiconductor solar absorbers includingSi and GaAs due to optical phonon and carrier scattering at high temperatures.In contrast to the popular polaron scattering mechanism, the CsPbI3 nanocrystal thin film demonstrates the strongest opticalphonon scattering mechanism among other inorganic-organic hybridperovskites, Si, and GaAs. This ultrafast dynamics study establishesa foundation for understanding the fundamental carrier drift propertiesthat drive perovskite nanocrystal optoelectronics.

Automated summary

We investigated the carrier drift dynamics in CsPbI3 nanocrystal thin films with a time resolution of sub 25 ps. The carriers exhibit band-like transport characteristics similar to traditional semiconductor solar absorbers (Si and GaAs) due to optical phonon and carrier scattering at high temperatures, prior to trapping. In contrast to popular polaron scattering mechanism, CsPbI3 nanocrystal thin film demonstrates the strongest optical phonon scattering mechanism among other inorganic-organic hybrid perovskites, Si, and GaAs. This ultrafast dynamics study provides a foundation for understanding the fundamental carrier drift properties in perovskite nanocrystal optoelectronics.