Controlled optical properties of water-soluble CdTe nanocrystals via anion exchange

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• 作者：Jing Li^a ; Jianguang Jia^a ; ^{jiajg@mail.buct.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yuan Lin^b ; Xiaowen Zhou^b ; ^{zhouxw66@iccas.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：CdTe nanocrystal ; Optical property ; Anion exchange ; Temperature
• 刊名：Journal of Colloid and Interface Science
• 出版年：2016
• 出版时间：1 February 2016
• 年：2016
• 卷：463
• 期：Complete
• 页码：69-74
• 全文大小：1189 K

文摘

We report a study on anion exchange reaction of CdTe nanocrystals with S²⁻ in aqueous solution under ambient condition. We found that the optical properties of CdTe nanocrystals can be well tuned by controlling the reaction conditions, in which the reaction temperature is crucially important. At low reaction temperature, the product nanocrystals showed blue-shifts in both absorption and PL spectra, while the photoluminescence quantum yield (PLQY) was significantly enhanced. When anion exchanges were carried out at higher reaction temperature, on the other hand, obvious red shifts in absorption and PL spectra accompanied by a fast increase followed by gradual decrease in PLQY were observed. On variation of S²⁻ concentration, it was found that the overall kinetics of Te²⁻ for S²⁻ exchanges depends also on [S²⁻] when anion exchanges were performed at higher temperature. A possible mechanism for anion exchanges in CdTe NCs was proposed.