Optical properties of AgI quantum dots embedded in a glass matrix

We report the fabrication, transmission electron microscopy investigation and linear optical properties of silver iodide quantum dots in an aluminaborosilicate host network structure. The nearly spherical quantum dots with radii ranging from 1.7 to 2 nm exhibit a pronounced excitonic absorption and intensive intrinsic photoluminescence in the intermediate confinement regime. The selective photoluminescence and photoluminescence excitation measurements revealed the fine structure in the spectra due to the splitting of the lowest exciton state by the electron-hole exchange interaction. A considerable enhancement of the exchange energy with decreasing quantum dot size is observed.