Improvement of emission intensity of PbS quantum dots in thick silica shell by initial coating in organic solvent

Abstract

Positioning of colloidal quantum dots (QDs) by nanoholes is applicable to fabricating quantum devices such as quantum circuits. A silica coating technique that facilitates the positioning manages the effective size of QDs while preserving the quantum state inside. In the reverse micelle method, which is commonly used for the silica coating, optical properties deteriorate due to the exposure of QD surface to moisture within the reverse micelle. We studied a thin silica coating on the surface of PbS QDs by pyrolyzing tetraethyl orthosilicate in an organic solvent before forming a thick silica shell by the reverse micelle method. As a result, highly luminous silica-coated PbS QDs with a diameter of about 110 nm were realized.

Polarization-controlled ultrasmall single photon emitter combining a quantum dot and an elliptical split ring metamaterial element

“…Silica coating of QDs is a technology that can increase apparent size of QDs to several hundred nanometers without making any changes to their quantum states. [24][25][26][27][28][29][30][31] By using silica-coated QDs, QD position control becomes much easier. The nanohole used for a single QD can be large, and if the metamaterial element is thick, the nanohole is not needed as the silica-coated QD is directly trapped there.…”