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Temperature-Dependent Photoluminescence of Silver-Indium-Sulfide Nanocrystals in Aqueous Colloidal Solutions |
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| Authors: | Oleksandr Stroyuk Alexandra Raevskaya Felix Spranger Prof Nikolai Gaponik Prof Dietrich R T Zahn |
| Institution: | 1. Semiconductor Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany;2. L.V. Pysarzhevsky Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Kyiv, 03028 Ukraine
Physical Chemistry, Technical University of Dresden, 01062 Dresden, Germany;3. Physical Chemistry, Technical University of Dresden, 01062 Dresden, Germany |
| Abstract: | The temperature dependence of the photoluminescence (PL) intensity of colloidal semiconductor nanocrystals (NCs) makes them an appealing option in bio-sensing applications. Here, we probed the temperature-dependent PL behavior of aqueous glutathione (GSH)-capped Ag?In?S (AIS) NCs and their core/shell AIS/ZnS heterostructures. We show that both core and core-shell materials reveal strong PL quenching upon heating from 10 to 80 °C, which is completely reversible upon cooling. The PL quenching is assigned to the thermally activated dissociation of complexes formed by ligands with the metal cations on the NC surface and the introduction of water into the NC coordination sphere. This unique mechanism of the thermal PL quenching results in a much higher temperature sensitivity of the aqueous colloidal AIS (AIS/ZnS) NCs as compared with previously reported analogs capped by covalently bound ligands. Our results are expected to stimulate further studies on aqueous ternary NCs as colloidal luminescent nano-thermometers applicable for ratiometric temperature sensing. |
| Keywords: | photoluminescence semiconductor quantum dots silver indium sulfide stretched exponent temperature dependence |