Trap-Enabled Long-Distance Carrier Transport in Perovskite Quantum Wells

Layered two-dimensional (2D) hybrid
perovskites are naturally formed
multiple quantum well (QW) materials with promising applications in
quantum and optoelectronic devices. In principle, the transport of
excitons in 2D perovskites is limited by their short lifetime and
small mobility to a distance within a few hundred nanometers. Herein,
we report an observation of long-distance carrier transport over 2
to 5 μm in 2D perovskites with various well thicknesses. Such
a long transport distance is enabled by trap-induced exciton dissociation
into long-lived and nonluminescent electron–hole separated
state, followed by a trap-mediated charge transport process. This
unique property makes 2D perovskites comparable with 3D perovskites
and other traditional semiconductor QWs in terms of a carrier transport
property and highlights their potential application as an efficient
energy/charge-delivery material.