摘要
用热壁外延法在氟金云母衬底上生长出了高质量 C6 0 薄膜 ,用原子力显微镜观察了样品的表面形貌 .测量并分析了不同厚度 C6 0 薄膜的紫外 -可见吸收光谱 .由测量的透射及反射光谱 ,经计算得到了吸收系数与入射光子能量的关系 .利用结晶半导体的带间跃迁理论 ,对禁戒的带间直接跃迁 hu→ t1 u和电偶极允许的带间直接跃迁 hu→ t1
High quality C 60 thin films are deposited on fluorophlogopite substrates by hot wall epitaxy method.The surface crystal morphology of C 60 thin films is observed under an atomic force microscopy.The UV Vis absorption spectra of C 60 thin films with different film thickness are analyzed, and the absorption coefficient α is calculated from the measured transmittance and the reflection spectra.Based on the interband transition theory of semiconductor, the values of h u→ t 1u (dipole forbidden) and h u→ t 1g (dipole allowed) optical band gaps are obtained from the analysis of the corresponding absorption coefficient α.
基金
北京市自然科学基金! (No.2 962 0 0 5 )
北京市科技骨干基金资助项目&&
