Dinelli Franco, Murgia Mauro, Levy Pablo, Cavallini Massimiliano, Biscarini Fabio, de Leeuw Dago M
Consiglio Nazionale delle Ricerche--Istituto per lo Studio dei Materiali Nanostrutturati-Sezione Bologna, Via P. Gobetti 101, I-40129 Bologna Italy.
Phys Rev Lett. 2004 Mar 19;92(11):116802. doi: 10.1103/PhysRevLett.92.116802.
Hole mobility in organic ultrathin film field-effect transistors is studied as a function of the coverage. For layered sexithienyl films, the charge carrier mobility rapidly increases with increasing coverage and saturates at a coverage of about two monolayers. This shows that the first two molecular layers next to the dielectric interface dominate the charge transport. A quantitative analysis of spatial correlations shows that the second layer is crucial, as it provides efficient percolation pathways for carriers generated in both the first and the second layers. The upper layers do not actively contribute either because their domains are smaller than the ones in the second layer or because the carrier density is negligible.
研究了有机超薄膜场效应晶体管中空穴迁移率与覆盖率的函数关系。对于层状六噻吩薄膜，电荷载流子迁移率随覆盖率的增加而迅速增加，并在约两个单层的覆盖率时达到饱和。这表明紧邻介电界面的前两个分子层主导着电荷传输。对空间相关性的定量分析表明，第二层至关重要，因为它为在第一层和第二层中产生的载流子提供了有效的渗流途径。上层不起积极作用，要么是因为它们的畴比第二层中的畴小，要么是因为载流子密度可以忽略不计。
