Systematic synthesis of different-sized AgInS <sub>2</sub> /GaS <sub> <i>x</i> </sub> nanocrystals for emitting the strong and narrow excitonic luminescence
Trần Thị Thu Hương, Nguyễn Thu Loan, Ung Thi Dieu Thuy, Nguyễn Thanh Tùng, HyukSu Han, Nguyen Quang Liem
Abstract
Abstract This paper presents for the first time the systematic synthesis of AgInS 2 (AIS) nanocrystals (NCs) with different sizes of 2.6–6.8 nm just by controlling only the reaction temperature. The synthesis of AIS core NCs was carried out in 2 steps: (i) synthesis of Ag 2 S NCs and then (ii) partial exchange of Ag + with In 3+ in the template Ag 2 S NCs. For step (i), Ag 2 S NCs of different sizes were synthesized by reaction of the Ag and S precursors at different temperatures of 30 °C to 130 °C, for the same reaction time of 30 min. For step (ii), AIS NCs were created by the exchange of Ag + with In 3+ at 120 °C for 60 min. Finally, GaS x was shelled on AIS core NCs to produce the AgInS 2 /GaS x core/shell structures. The synthesized AIS/GaS x NCs demonstrate the clear excitonic absorptions and strong, narrow excitonic luminescence peaking at 530–606 nm depending on the size of AIS core NCs.