Efficient Interlayer Exciton Transport in Two-Dimensional Metal-Halide Perovskites.

We present transient microscopy measurements of interlayer energy transport in (PEA)₂PbI₄ perovskite. We find efficient interlayer exciton transport (0.06 cm²/s), which translates into a diffusion length that exceeds 100 nm and a sub-ps timescale for energy transfer. While still slower than in-plane exciton transport (0.2 cm²/s), our results show that excitonic energy transport is considerably less anisotropic than charge-carrier transport for 2D perovskites.