Spontaneous buildup of giant surface potential by vacuum deposition of Alq3 and its removal by visible light irradiation
Spontaneous buildup of giant surface potential by vacuum deposition of Alq3 and its removal by visible light irradiation
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DOI：
10.1063/1.1518759
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发表时间：
2002-12-15
影响因子：
3.2
通讯作者：
Seki, K
中科院分区：
文献类型：
--
作者：
Ito, E;Washizu, Y;Seki, K
在黑暗条件下，我们观察到在Au衬底上真空沉积三(8-羟基喹啉)铝(III)(Alq(3))的表面电位(SP)有很高且持续的自发增强。用开尔文探针法测得的表面电位在560 nm处达到28V，Alq(3)薄膜表面带正电荷。我们提出了一个模型，在该模型中，Alq(3)分子偶极矩的择优取向是SP积聚的根源。在黑暗条件下，Alq(3)的沉积也极大地增加了二次谐波的产生强度，这支持了偶极层积累的概念。用可见光照射Alq(3)分子，这种巨大的表面电势几乎被完全消除，沉积过程中的照射也阻止了SP的积累。(C)2002年美国物理研究所。
We observed high and persistent spontaneous buildup of the surface potential (SP) upon vacuum deposition of tris(8-hydroxyquinolinato) aluminum(III) (Alq(3)) on an Au substrate under dark conditions. SP determined by the Kelvin probe method reached 28 V at a thickness of 560 nm and the surface of the Alq(3) film was positively charged. We propose a model in which preferential orientation of the dipole moments of Alq(3) molecules is the origin of this buildup of the SP. The intensity of second-harmonic generation was also dramatically increased by the deposition of Alq(3) under dark conditions, which supports the notion of a buildup of dipole layers. This giant surface potential was almost completely removed by irradiation of Alq(3) molecules with visible light, and irradiation during deposition also prevented the buildup of SP. (C) 2002 American Institute of Physics.