Miniaturized photonic sources based on semiconducting two-dimensional (2D) materials offer new technological opportunities. The quantum-confined 2D electronic structure aligns the exciton transition dipole moment parallel to the surface plane, enhancing light outcoupling. This paper reports decoupled multi-quantum-well superlattices of colloidal quantum wells of lead halide perovskites with ultrathin quantum barriers (6.5 Å). Crystallographic and 2D k-space spectroscopic analysis confirms interlayer decoupling and predominantly in-plane transition dipole moment orientation, independent of stacking layer and barrier thickness.

Jakub Jagielski, Simon F. Solari, Lucie Jordan, Declan Scullion, Balthasar Blülle, Yen-Ting Li, Frank Krumeich, Yu-Cheng Chiu, Beat Ruhstaller, Elton J.G. Santos, Chih-Jen Shih