Photon Reabsorption in Mixed CsPbCl3:CsPbI3Perovskite Nanocrystal Films for Light-Emitting Diodes.
Cesium lead halide nanocrystals, CsPbX3(X = Cl, Br, I), exhibit photoluminescence quantum efficiencies approaching 100% without the core-shell structures usually used in conventional semiconductor nanocrystals. These high photoluminescence efficiencies make these crystals ideal candidates for light-emitting diodes (LEDs). However, because of the large surface area to volume ratio, halogen exchange between perovskite nanocrystals of different compositions occurs rapidly, which is one of the limiting factors for white-light applications requiring a mixture of different crystal compositions to achieve a broad emission spectrum. Here, we use mixtures of chloride and iodide CsPbX3(X = Cl, I) perovskite nanocrystals where anion exchange is significantly reduced. We investigate samples containing mixtures of perovskite nanocrystals with different compositions and study the resulting optical and electrical interactions. We report excitation transfer from CsPbCl3to CsPbI3in solution and within a poly(methyl methacrylate) matrix via photon reabsorption, which also occurs in electrically excited crystals in bulk heterojunction LEDs.
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Nathaniel J L K
NJ
Davis
Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
Francisco J
FJ
de la Peña
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Maxim
M
Tabachnyk
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Johannes M
JM
Richter
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Robin D
RD
Lamboll
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Edward P
EP
Booker
Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
Florencia
F
Wisnivesky Rocca Rivarola
Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
James T
JT
Griffiths
Department of Materials Science and Metallurgy, University of Cambridge , 27 Charles Babbage Road, Cambridge, CB3 0FS, U.K.
Caterina
C
Ducati
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
S Matthew
SM
Menke
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Felix
F
Deschler
Cavendish Laboratory, University of Cambridge , J.J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
Neil C
NC
Greenham