High-efficiency energy transfer in perovskite heterostructures

Here, we report the energy transfer in (PEA) 2 PbI 4 /MAPbBr 3 perovskite heterostructures. Under two-photon excitation, the photoluminescence (PL) emission of the (PEA) 2 PbI 4 flake is nearly completely quenched, while that of the MAPbBr 3 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) 2 PbI 4 flake to the MAPbBr 3 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.