Air-Stable n-Doped Colloidal HgS Quantum Dots.
HgS nanocrystals show a strong mid-infrared absorption and a bleach of the near-infrared band edge, both tunable in energy and reversibly controlled by exposure to solution ions under ambient conditions. The same effects are obtained by applying a reducing electrochemical potential, confirming that the mid-infrared absorption is the intraband transition of the quantum dot. This is the first time that stable carriers are present in the quantum state of strongly confined quantum dot in ambient conditions. The mechanism by which doping is achieved is attributed to the rigid shifts of the valence and conduction band with respect to the environment, similar to the sensitivity of the work function of surfaces to adsorbates.
The James Franck Institute, 929 East 57th Street, The University of Chicago, Chicago, Illinois 60637, United States.
Kwang Seob
KS
Jeong
The James Franck Institute, 929 East 57th Street, The University of Chicago, Chicago, Illinois 60637, United States.
Zhiyou
Z
Deng
The James Franck Institute, 929 East 57th Street, The University of Chicago, Chicago, Illinois 60637, United States.
Sean
S
Keuleyan
The James Franck Institute, 929 East 57th Street, The University of Chicago, Chicago, Illinois 60637, United States.
Heng
H
Liu
The James Franck Institute, 929 East 57th Street, The University of Chicago, Chicago, Illinois 60637, United States.
Philippe
P
Guyot-Sionnest
air-stable n-doped HgS colloidal quantum dots; photoluminescence of quantum dots in midwavelength infrared range; spectroelectrochemistry; steady-state intraband absorption; surface doping