Influence of the synthesis conditions on the optical properties of CuInS2 nanocrystals
Abstract
This paper presents the results on the synthesis ofCuInS2 nanocrystals (CIS NCs) by using heating-up method, in which NCs are nucleated by chemical reaction and developed at high temperature in diesel solvent. The influence of technical parameters such as the reaction temperature, growth time, Cu:In molar ratio from the precursors on the optical properties (absorption and photoluminescence) of CIS NCs were studied systematically. In particular, the quality of CIS NCs formed and developed in the temperature range from 200°C to 230°C for 15 minutes and the Cu:In ratio of 0.5 : 1 ÷ 1.5 :1 was investigated. Based on the absorption and photoluminescence characteristics one could see that the obtained CIS NCs have the best quality by synthesizing at 210oC in diesel. It is found that the optical property of CIS NCs is significantly improved by adding Zn ions (the amount of < 10 %) to precursors in the synthesis that show the excitonic absorption clearer.