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Unusual Optical Properties of Mn‐doped ZnO: The Search for a New Red Pigment—A Combined Experimental and Theoretical Study
Author(s) -
Saal Hilkka,
Binnewies Michael,
Schrader Marius,
Börger Alexander,
Becker KlausDieter,
Tikhomirov Viatcheslav A.,
Jug Karl
Publication year - 2009
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200802667
Subject(s) - valence (chemistry) , manganese , doping , crystallite , zinc , chemistry , absorption spectroscopy , electronic structure , atomic electron transition , divalent , spectral line , diffuse reflection , analytical chemistry (journal) , electron paramagnetic resonance , materials science , crystallography , nuclear magnetic resonance , optics , computational chemistry , physics , optoelectronics , organic chemistry , chromatography , astronomy
A pigment of your imagination : A range of polycrystalline solid solutions of a zinc‐rich Zn x −1 Mn x O system (see figure) have been prepared and studied in terms of their colour, diffuse reflectance spectra, Mn valence state and electronic structure. The intense optical absorption arises from Mn 2+ doping and is thought to be due to forbidden or partially forbidden transitions between the valence and the conduction band.We report an investigation of zinc‐rich polycrystalline solid solutions of the Zn 1− x Mn x O system concerning the colour, the diffuse reflectance spectra, the valence state of manganese and the electronic structure. Samples were prepared by a chemical‐vapour‐transport‐assisted route and optimized with respect to colour strength. In agreement with previous experimental results, EPR studies showed that manganese is in the divalent charge state. The nature of the very intense optical absorption, which is caused by Mn 2+ doping and determines the colour of the material, is discussed. It is argued that the Mn 2+ ‐induced optical absorption is due to forbidden or partially forbidden transitions between the valence and the conduction band that involve Mn admixed states. This assignment is also confirmed by quantum chemical calculations using the semiempirical molecular orbital method MSINDO.