Wang Zhenguang, Chen Bingkun, Susha Andrei S, Wang Weihua, Reckmeier Claas J, Chen Rui, Zhong Haizheng, Rogach Andrey L
Department of Physics and Materials Science and Centre for Functional Photonics (CFP) City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong SAR.
Department of Physics and Materials Science and Centre for Functional Photonics (CFP) City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong SAR; Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China.
Adv Sci (Weinh). 2016 Jun 21;3(11):1600182. doi: 10.1002/advs.201600182. eCollection 2016 Nov.
Most of the present-day down-conversion white light-emitting devices (WLEDs) utilize rare-earth elements, which are expensive and facing the problem of shortage in supply. WLEDs based on the combination of orange and blue emitting copper nanoclusters are introduced, which are easy to produce and low in cost. Orange emitting Cu nanoclusters (NCs) are synthesized using glutathione as both the reduction agent and stabilizer, followed by solvent induced aggregation leading to the emission enhancement. Photoluminescence quantum yields (PL QY) of 24% and 43% in solution and solid state are achieved, respectively. Blue emitting Cu nanoclusters are synthesized by reduction of polyvinylpyrrolidone supported Cu(II) ions using ascorbic acid, followed by surface treatment with sodium citrate which improves both the emission intensity and stability of the clusters, resulting in the PL QY of 14% both in solution and solid state. All-copper nanocluster based down-conversion WLEDs are fabricated by integrating powdered orange and blue emitting Cu NC samples on a commercial GaN LED chip providing 370 nm excitation. They show favorable white light characteristics with Commission Internationale de l'Eclairage color coordinates, color rendering index, and correlated color temperature of (0.36, 0.31), 92, and 4163 K, respectively.
目前大多数下转换白光发光器件（WLED）都使用稀土元素，这些元素价格昂贵且面临供应短缺的问题。本文介绍了基于橙色和蓝色发光铜纳米簇组合的WLED，其易于制备且成本低廉。以谷胱甘肽作为还原剂和稳定剂合成橙色发光铜纳米簇（NCs），随后通过溶剂诱导聚集导致发光增强。溶液态和固态的光致发光量子产率（PL QY）分别达到24%和43%。通过用抗坏血酸还原聚乙烯吡咯烷酮负载的Cu（II）离子合成蓝色发光铜纳米簇，随后用柠檬酸钠进行表面处理，这提高了纳米簇的发光强度和稳定性，溶液态和固态的PL QY均为14%。通过将橙色和蓝色发光Cu NC粉末样品集成在提供370 nm激发的商用GaN LED芯片上，制备了全铜纳米簇基下转换WLED。它们显示出良好的白光特性，国际照明委员会色坐标、显色指数和相关色温分别为（0.36, 0.31）、92和4163 K。
