Bankole Owolabi M, Achadu Ojodomo J, Nyokong Tebello
Department of Chemistry, Rhodes University, Grahamstown, 6140, South Africa.
J Fluoresc. 2017 Mar;27(2):755-766. doi: 10.1007/s10895-016-2008-8. Epub 2017 Jan 4.
This study reports the development of functional optical limiting materials composed of pristine graphene (GQDs), nitrogen-doped (NGQDs) and sulfur-nitrogen co-doped (SNGQDs) graphene quantum dots covalently linked to mono-amino substituted zinc phthalocyanine (Pc). Open aperture Z-scan technique was employed to monitor the behaviour of the conjugates under tightly focussed Gaussian laser beam using a mode-locked Nd:YAG laser delivering 10 nanosecond (FWHM) pulses at 532 nm wavelength. Nonlinear effect due to reverse saturable absorption was the predominant mechanism; and was attributed to the moderately enhanced triplet population. The major factor(s) responsible for the enhanced nonlinearities in the Pc-NGQDs and Pc-SNGQDs was fully described and attributed to the surface defects caused by the presence of heteroatoms of N and S.
本研究报告了由原始石墨烯量子点（GQDs）、氮掺杂（NGQDs）和硫氮共掺杂（SNGQDs）的石墨烯量子点与单氨基取代的锌酞菁（Pc）共价连接而成的功能性光限幅材料的研制情况。采用开孔Z扫描技术，使用锁模Nd:YAG激光器在532 nm波长下输出10纳秒（半高宽）脉冲，在紧聚焦高斯激光束下监测共轭物的行为。由反向饱和吸收引起的非线性效应是主要机制，这归因于三重态粒子数的适度增加。对Pc-NGQDs和Pc-SNGQDs中增强非线性的主要因素进行了全面描述，并归因于N和S杂原子的存在所导致的表面缺陷。
