Fig. 1: Optical characteristics of CTE formation in 2D perovskite heterostructures.
From: Establishing charge-transfer excitons in 2D perovskite heterostructures
a Absorption and PL spectra are shown for 2D perovskite heterostructured [(PEA2PbI4)0.999:(PEA2SnI4)0.001] film. The absorption spectrum indicates that the bandgap is governed by the host (PEA2PbI4) component in the heterostructures. The PL spectrum is dominated by a broad emission peaked at 669 nm with a spectral shoulder at 614 nm from the guest (PEA2SnI4) and the intrinsic emission (peaked at 531 nm) from the host (PEA2PbI4). b PL spectrum is shown for 2D perovskite heterostructured [(PEA2SnI4)0.999:(PEA2PbI4)0.001] film after switching host and guest components. The broad emission is observed with the peak position at 697 nm, in addition to intrinsic emission (peaked at 524 and 627 nm) from host (PEA2PbI4) and guest (PEA2SnI4) components. The PL spectra for pristine PEA2PbI4 and PEA2SnI4 films are also shown as reference. c Schematic diagram illustrates the formation of CTEs at the interfaces between PEA2PbI4 and PEA2SnI4 components in 2D perovskite heterostructures [(PEA2PbI4)1−x:(PEA2SnI4)x].
