Colloidal HgTe nanocrystals with widely tunable narrow band gap energies: from telecommunications to molecular vibrations.
A convenient, aqueous-based synthesis of stable HgTe nanocrystals with widely size-tunable room temperature emission between wavelengths of 1.2 to 3.7 mum is demonstrated. By the choice of the thiols, applied as stabilizers, we optimized the growth dynamics, the luminescence quantum yields (up to 40%), and a ligand-exchange procedure, required to transfer the nanocrystals from water to nonpolar organic solvents. The latter is greatly improved and facilitated by the use of mercaptoethylamine as initial stabilizer. The possibility to tune the HgTe nanocrystal sizes from 3 to 12 nm and to control their surface functionalities (hydrophobic and hydrophilic) makes them very promising for the development of infrared optical devices, emitting in the wavelength region between the telecommunications and the molecular vibrations.
Institute of Semiconductor and Solid State Physics, Johannes Kepler University, Linz A-4040 Linz, Austria. maksym.kovalenko@jku.at
Maksym V
MV
Kovalenko
Erich
E
Kaufmann
Dietmar
D
Pachinger
Jürgen
J
Roither
Martin
M
Huber
Julian
J
Stangl
Günter
G
Hesser
Friedrich
F
Schäffler
Wolfgang
W
Heiss