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HL: Fachverband Halbleiterphysik
HL 100: ZnO and its relatives
HL 100.7: Vortrag
Freitag, 20. März 2015, 11:15–11:30, EW 203
Blue shifting the photoluminescence of ZnO by doping with amino acids — •Marlene Lamers1,3, Verena Baumann1,3, Anastasia Brif2, Guy Ankonina4, Alexander Urban1,3, Jessica Rodríguez-Fernández1,3, Boaz Pokroy2, and Jochen Feldmann1,3 — 1Photonics and Optoelectronics Group, Ludwig-Maximilians-Universität, Munich — 2Department of Materials Science and Engineering and the Russell Berrie Nanotechnology Institute of Technology, Haifa, Israel — 3Nanosystems Initiative Munich (NIM), Munich — 4Photovoltaic lab, Department of Electrical Engineering, Technion Israel Institute of Technology, Haifa, Israel
Zinc oxide (ZnO) is an attractive semiconductor due to its wide and direct bandgap in the UV region (Eg = 3.4 eV), its large free-exciton binding energy (60 meV) and its strong photoluminescence even at room temperature. Bandgap tuning is of special interest to extend the spectral range of ZnO based devices. Recently, it has been demonstrated by optical reflection spectroscopy that the bandgap of zinc oxide can be engineered by intracrystalline incorporation of amino acids due to an increased lattice strain [1]. We have performed photoluminescence and absorption experiments, which reveal a controlled blue-shift of the bandgap emission for amino acid doped ZnO vs. pure ZnO. Additionally, the ratio of band-edge-to-defect emission can be significantly enhanced by post-synthetic heat treatment. Morphological changes will be discussed as a possible reason for these observations.
[1] A. Brif, G. Ankonina, C. Drathen, B. Pokroy, Adv. Mater. (2014) 26, 477.