LAUSR

Here, we report the energy transfer in (PEA)2PbI4/MAPbBr3 perovskite heterostructures. Under two-photon excitation, the photoluminescence (PL) emission of the (PEA)2PbI4 flake is nearly completely quenched, while that of the MAPbBr3 microplate is greatly increased (6.5 folds higher) in the heterostructure. The opposite variation character of the PL emissions is attributed to the radiative energy transfer from the (PEA)2PbI4 flake to the MAPbBr3 microplate. The radiative energy transfer occurs on an ultrafast timescale with a high efficiency (~100%). In addition, a strongly thickness- and wavelength-dependent interlayer interaction is observed under one-photon excitation. This work advocates great promise for revealing the interlayer interaction of perovskite heterostructures and developing high-performance optoelectronic devices.