Monodispersed cation-disordered cubic AgInS2 nanocrystals with enhanced fluorescence

Monodispersed metastable cubic AgInS2 nanocrystals with an average size of around 2.5 nm are obtained via a solution-phase reaction. In contrast with the usual chalcopyrite and orthorhombic phase, Ag+ and In3+ cations in metastable cubic AgInS2 are randomly coordinated by four S2- anions. A phase transition from cation-disordered cubic to orthorhombic AgInS2 occurs with the increased reaction temperature or elongated reaction time. The photoluminescence quantum yield of cation-disordered cubic AgInS2 nanocrystals could reach 10% at room temperature, which is much higher than that of orthorhombic AgInS2 nanocrystals obtained via a similar approach.