title: Electrostatic effect of Au nanoparticles on near-infrared photoluminescence from Si/SiGe due to nanoscale metal/semiconductor contact.
abstract: Photoluminescence (PL) from Si and SiGe is comprehensively modified by Au NPs under excitation without surface plasmon resonance. Moreover, the PL sensitively depends on the size of the Au NPs, the excitation power and the thickness of the Si layer between the Au NPs and SiGe. A model is proposed in terms of the electrostatic effects of Au NPs naturally charged by electron transfer through the nanoscale metal/semiconductor Schottky junction without an external bias or external injection of carriers. The model accounts well for all the unique PL features. It also reveals that Au NPs can substantially modify the energy band structures, distribution and transition of carriers in the nanoscale region below the Au NPs. Our results demonstrate that Au NPs on semiconductors can efficiently modulate light-matter interaction.
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China. Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, People's Republic of China.
authors.forename: Yefei
authors.initials: Y
authors.lastname: Yin
authors.forename: Ze
authors.initials: Z
authors.lastname: Wang
authors.forename: Shuguang
authors.initials: S
authors.lastname: Wang
authors.forename: Yujie
authors.initials: Y
authors.lastname: Bai
authors.forename: Zuimin
authors.initials: Z
authors.lastname: Jiang
authors.forename: Zhenyang
authors.initials: Z
authors.lastname: Zhong