Tunable photoluminescence from the visible to near-infrared wavelength region of non-stoichiometric AgInS2 nanoparticles

Optical characterization of the AgInS2 nanocrystals synthesized in aqueous media under stoichiometric conditions

“…Incorporation of Zn into AgInS 2 has been shown to be another efficient tool to improve the PL color tunability of the NCs [2,3,10,14,15], while coverage of the AgInS 2 core with a ZnS shell [6,10,13] allows increasing the PL quantum yield up to 80% [10]. The PL of the AgInS 2 NCs irrespective of the method of synthesis is ascribed to the radiative recombination of carriers via intragap levels formed by structural defects [2,12,13,[18][19][20]. This causes long PL lifetimes and large Stokes shifts which are highly important for the biomedical imaging.…”

“…Development of the methods for synthesis of AgInS 2 nanocrystals (NCs) with a tunable band gap and a high photoluminescence (PL) quantum yield opened new prospects for their application in lightemitting devices [2,3], photovoltaic solar cells [4] and lowtoxic photostable molecular probes [5,6]. Up to date, different strategies have been proposed for synthesis of the AgInS 2 NCs such as: hydrothermal [7], solvothermal [8,9] and hot injection methods [10][11][12][13][14][15], aqueous synthetic route [16] etc. Compared with the organic based approaches, the synthesis in aqueous media is more reproducible, low-cost, environment-friendly, biocompatible, and the as-prepared samples are water soluble, which is especially important for further bio-medical applications [16].…”

A new strategy for synthesizing AgInS2 quantum dots emitting brightly in near-infrared window for in vivo imaging

“…Among these ternary nanocrystals, AgInS 2 QDs have direct band gap and low toxicity, and have a large absorption in the visible and NIR regions 23,24 . With a band gap of ~1.8 eV at room temperature, the AgInS 2 QDs can emit in the near-infrared region with high extinction coefficients, which offers an intriguing alternative for biological imaging applications 25 .…”

Colloidal semiconductor quantum dots; syntheses, properties and applications

“…A PLQY of >80% was reported for CuInS 2 /CdS core/shell QDs, 46) and approximately 70% of PLQY was attained for AgInS 2 based QDs. 47) However, the Stokes shifts of reported CuInS 2 QDs are generally large. 36),45),48)50) The exception to this was the PL emission of CuInS 2 /ZnS core/shell QDs with a Stokes shift of ³60 meV, reported by Nose et al 51) This emission was unfortunately very weak, and an intense emission with a large Stokes shift simultaneously appeared.…”