Controlling the dimension of the quantum resonance in CdTe quantum dot superlattices fabricated via layer-by-layer assembly

• Published in: Nature communications Vol. 11; no. 1; p. 5471
• Main Authors: Lee, TaeGi, Enomoto, Kazushi, Ohshiro, Kazuma, Inoue, Daishi, Kikitsu, Tomoka, Hyeon-Deuk, Kim, Pu, Yong-Jin, Kim, DaeGwi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.10.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 140/125; 147/143; 639/301/1019/1021; 639/925/357/1017; Assembly; Cadmium tellurides; Dependence; Electron states; Electrons; Energy; Excitation spectra; Fabrication; Humanities and Social Sciences; Luminescence; multidisciplinary; Optoelectronic devices; Photoluminescence; Photons; Photovoltaic cells; Polyelectrolytes; Quantum dots; Resonance; Science; Science (multidisciplinary); Solar cells; Superlattices; Wave functions
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-19337-0

In quantum dot superlattices, wherein quantum dots are periodically arranged, electronic states between adjacent quantum dots are coupled by quantum resonance, which arises from the short-range electronic coupling of wave functions, and thus the formation of minibands is expected. Quantum dot superlattices have the potential to be key materials for new optoelectronic devices, such as highly efficient solar cells and photodetectors. Herein, we report the fabrication of CdTe quantum dot superlattices via the layer-by-layer assembly of positively charged polyelectrolytes and negatively charged CdTe quantum dots. We can thus control the dimension of the quantum resonance by independently changing the distances between quantum dots in the stacking (out-of-plane) and in-plane directions. Furthermore, we experimentally verify the miniband formation by measuring the excitation energy dependence of the photoluminescence spectra and detection energy dependence of the photoluminescence excitation spectra. Designing quantum dot superlattices remains a challenge. Here, the authors present CdTe quantum dot superlattices via the layer-by-layer assembly and verify the miniband formation by measuring the excitation energy the dependence of the photoluminescence spectra and the detection energy dependence of the excitation spectra.