Electron-stimulated fragmentation mechanism for fullerene films on Si(111)-(7x7) surfaces: Dependence on thickness and electron flux

被引：6

作者：

Bolotov, L ^{[1
]}

Kanayama, T ^{[1
]}

机构：

[1] Natl Inst Adv Ind Sci & Technol AIST, Joint Res Ctr Atom Technol, Tsukuba, Ibaraki 3058562, Japan

来源：

PHYSICAL REVIEW B | 2003年 / 68卷 / 03期

关键词：

D O I：

10.1103/PhysRevB.68.033404

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We studied the fragmentation of ultrathin [1-6 ML (monolayer)] C-60 films on Si(111)-(7X7) surfaces under intense pulse electron irradiation using a scanning tunneling microscope for field-emission electron irradiation below (20 eV) and above (45 eV) the fragmentation threshold energy. We assessed the fragmentation yield for various film thicknesses and electron fluxes. Fragmentation resulting in coalesced spheroid structures becomes less efficient in thinner films owing to faster energy transfer into the substrate. Our observation of flux dependence revealed that two-electron excitation causes fragmentation at sub-threshold energy when the excitation rate exceeds the excited-state decay rate (similar to10(9) s(-1) for 4-ML thickness).

引用

页数：4

共 30 条

[1] ELECTRONIC-ENERGY TRANSFER AT SEMICONDUCTOR INTERFACES .1. ENERGY-TRANSFER FROM TWO-DIMENSIONAL MOLECULAR FILMS TO SI(111) [J].