Phase change induced quantization in NIR emitting Ag2S nanocrystals: Structural and optical response for solar energy applications

Abstract Quantum dots sensitized solar cells with low cost and simultaneously achieving high power conversion efficiency have been of great interest. The origination of quantum confinement in a system dramatically improves its physical properties. Here we report the phase change induced quantization in NIR emitting Ag 2 S quantum dots (QDs) by analysing their structural and optical response. Ag 2 S QDs have been synthesized by bottom-up technique. Structural and morphology of nanocrystals have been investigated by XRD, TEM and Raman spectroscopy. The size-dependent excited state optical properties of Ag 2 S QDs have been systematically investigated by UV-VIS-NIR spectroscopy and photoluminescence (PL). Experimentally, we determine the quantum confinement in the Ag 2 S QDs due to change in phase and change in the size of the particles. The synthesized QDs via this mode may be suitable for capturing solar energy, especially in NIR region.