Energy level alignment at interfaces with pentacene : metals versus conducting polymers
Energy level alignment at interfaces with pentacene : metals versus conducting polymers
复制标题
并五苯界面的能级排列：金属与导电聚合物
DOI：
10.1016/j.apsusc.2004.10.128
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发表时间：
2005
影响因子：
6.7
通讯作者：
J. Rabe
中科院分区：
文献类型：
--
作者：
N. Koch;A. Elschner;R. Johnson;J. Rabe
紫外光电子能谱用于确定并五苯和两种根本不同的电极材料之间形成的功函数 和空穴注入势垒 Δhof 界面：（i）包含聚（3,4-乙撑二氧噻吩）和磺酸盐部分的导电聚合物，以及（ii）具有化学吸附的 Cl 的 Au。在并五苯沉积之前，这些基底的 ψ 对于聚合物来说覆盖了 4.25-5.15eV 的较宽范围，对于 Au-Cl 则延伸至 5.8eV。尽管 phi 存在巨大差异，但发现并五苯沉积后的 Δh 在所有情况下几乎相同（约 0.35eV）。 Δh 独立于初始表面 phi 的机制被认为是导致阳离子并五苯物质的界面电荷转移反应。将这些发现与并五苯和清洁金属表面之间的界面进行比较，发现 Δh 随着基材 phi 的增加而减少。
Ultraviolet photoemission spectroscopy was used to determine the work function ϕ and the hole injection barriers Δhof interfaces formed between pentacene and two fundamentally different electrode materials: (i) conductive polymers comprising poly(3,4-ethylenedioxythiophene) and sulfonate moieties, and (ii) Au with chemisorbed Cl. ϕ of these substrates before pentacene deposition covers a wide range of 4.25–5.15eV for the polymers, and extends to 5.8eV for Au–Cl. Despite this huge variation in ϕ, Δhafter pentacene deposition is found to be almost identical for all cases (≈0.35eV). The mechanism responsible for Δhbeing independent of initial surface ϕ is proposed to be an interfacial charge transfer reaction leading to cationic pentacene species. These findings are compared to interfaces between pentacene and clean metal surfaces, where Δhwas found to decrease with increasing substrate ϕ.