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Spatially Resolved Multi-Color CsPbX3 Nanowire Heterojunctions via Anion Exchange

Multi-Color CsPbX3 Nanowire Heterojunctions. (a) PL image of a CsPbBr3 - CsPbCl3 heterojunction. (b) Confocal PL image of a CsPbI3 - CsPbBr3 - CsPbCl3 heterojunction. (c) AFM and (d) KPFM profile of a CsPbBr3 - CsPbCl3 heterojunction showing the height and electronic structure contrast.

Scientific Achievement
Developed a method to fabricate spatially resolved multi-color CsPbX3 (X = Cl, Br, I) semiconductor nanowire heterojunctions with high resolution.

Significance and Impact
This approach offers new opportunities in fundamental understanding of the anion exchange / transport in halide perovskites as well as applications in multi color LEDs and Lasers.

Research Details

  • Semiconductor heterojunction is a key building block in modern electronics and optoelectronics.
  • Combined anion exchange chemistry and electron-beam lithography to fabricate halide perovskite nanowire heterojunctions with spatial resolution greater than a few hundred nanometers.
  • Confocal photoluminescence (PL) mapping shows different PL at different sections, and Kelvin probe force microscopy (KPFM) shows distinct electronic states across the interface of the heterojunctions.

L. Dou, M. Lai, Ch. S. Kley, Y. Yang, C.G. Bischak, D. Zhang, S.W. Eaton, N.S. Ginsberg, P. Yang, PNAS (2017) doi:10.1073/pnas.1703860114