Tuning Optical Properties of AgInS2 Quantum Dots by the Change of Ag-In Stoichiometry for their Light-emitting Applications

Due to environmental friendly composition and low toxicity together with high quantum yield ternary I-III-IV semiconductor nanocrystals competes successfully with well-understood II-IV quantum dots. However, the undeveloped synthesis procedure, a vast number of compounds, and competing reactions as well as poor understanding of the origin of their optical properties leave a wide place to research. AgInS2 quantum dots were synthesized in aqueous media by adding of sulfur precursor solution to the solution containing Ag and different concentrations of In cations together with mercaptoacetic acid as a stabilizer. We have shown the complex dependence of the optical properties of AgInS2 quantum dots on In to Ag precursor ratio arising from the changing of intrinsic point defect structure. This dependence opens the way of tuning their color emission for light-emitting devises creation.