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.
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.
- 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.