Molecular control over semiconductor surface electronic properties: Dicarboxylic acids on CdTe, CdSe, GaAs, and InP
Molecular control over semiconductor surface electronic properties: Dicarboxylic acids on CdTe, CdSe, GaAs, and InP
复制标题
DOI：
10.1021/ja9906150
复制
发表时间：
1999-11-17
影响因子：
15
通讯作者：
Ellis, AB
中科院分区：
文献类型：
--
作者：
Cohen, R;Kronik, L;Ellis, AB
我们提出了“设计规则”的选择分子实现电子控制半导体表面，使用一个简单的分子轨道模型。大多数电子器件的性能关键取决于它们的表面电子性质，即，表面能带弯曲和表面复合速度。对于半导体，这些性质取决于表面态的密度和能量分布。该模型是基于表面态分子，HOMO-LUMO-Like分子和半导体之间的相互作用。我们测试它通过使用接触电位差，表面光电压谱，时间和强度分辨的光致发光测量的组合。有了这些，我们表征的相互作用的两种类型的双官能二羧酸，前线轨道能级可以系统地改变，与空气暴露的CdTe，CdSe，InP，和GaAs表面。分子以单层的形式化学吸附在半导体上。该模型解释了这种相互作用的广泛变化的电子后果，并表明它们是由表面态能量位置和分子-表面态耦合的强度决定的。因此，本研究结果可以作为指导方针的分子辅助表面工程的半导体。
We present "design rules" for the selection of molecules to achieve electronic control over semiconductor surfaces, using a simple molecular orbital model. The performance of most electronic devices depends critically on their surface electronic properties, i.e., surface band-bending and surface recombination velocity. For semiconductors, these properties depend on the density and energy distribution of surface states. The model is based on a surface state-molecule, HOMO-LUMO-Like interaction between molecule and semiconductor. We test it by using a combination of contact potential difference, surface photovoltage spectroscopy, and time- and intensity-resolved photoluminescence measurements. With these, we characterize the interaction of two types of bifunctional dicarboxylic acids, the frontier orbital energy levels of which can be changed systematically, with air-exposed CdTe, CdSe, InP, and GaAs surfaces. The molecules are chemisorbed as monolayers onto the semiconductors. This model explains the widely varying electronic consequences of such interaction and shows them to be determined by the surface state energy position and the strength of the molecule-surface state coupling. The present findings can thus be used as guidelines for molecule-aided surface engineering of semiconductors.