Nonlinear Optical Properties of PbS Nanocrystals Grown in Polymer Solutions

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• 作者：Daniel J. Asunskis ; Igor L. Bolotin ; Luke Hanley
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：July 3, 2008
• 年：2008
• 卷：112
• 期：26
• 页码：9555 - 9558
• 全文大小：765K
• 年卷期：v.112,no.26(July 3, 2008)
• ISSN：1932-7455

文摘

Lead sulfide nanocrystals were grown in toluene solutions of poly(2-methoxy-5-(2′-ethyl-hexyloxy)-p-phenylene vinylene, polyethylene, poly(1-butene), poly(1-decene), and polystyrene. The PbS nanocrystal diameter was controlled by the polymer used for synthesis and ranged from 4 to 9 nm. Strong nonlinear absorption was observed in open aperture Z-scan measurements of solutions containing the synthesized nanocomposites. The best fit to the experimental data gave high values for β_eff in the range of 100−200 cm/GW. The nonlinear absorption of these polymer grown nanocrystals was not observed in nanocrystals grown in polyvinyl alcohol or with oleic acid capping. These differences in nonlinear optical absorption were due to surface chemistry, as the polymer synthesized nanocrystals were free of strongly bonding groups such as surfactant capping or hydroxyl groups. The β_eff values in these materials also showed no dependence on nanocrystal size.