张咪同学的论文"Tuning Electrical and Raman Scattering Properties of Cadmium Sulfide Nanoribbons via Surface Charge Transfer Doping"发表在J.Phys.Chem.C上

2019-06-04     来源:站内    关键词:揭建胜课题组     浏览量:353


Abstract

Surface charge transfer doping (SCTD) has emerged as an efficient approach to tune the electrical and optical properties of semiconductor nanostructures. As an important II-VI semiconductor, cadmium sulfide (CdS) nanostructures possess superior optoelectronic properties. However, SCTD on the CdS nanostructures remains a challenge, and the underlying mechanism for optical property modulation is unclear. Herein, we demonstrate that both the electrical and Raman scattering properties of CdS nanoribbons (NRs) can be tuned by using MoO3 and benzyl viologen (BV) as surface dopants. The MoO3 (or BV) molecules, which have high work function (or strong reducing capability), can extract (or inject) electrons from (or into) the CdS NRs because of the large difference in energy levels, leading to the electron depletion (or accumulation) within the CdS NRs. By controlling the amount of surface dopants, the electron concentration as well as resistivity of the CdS NRs can be readily modulated. Significantly, Raman scattering properties of the CdS NRs can be fine-tuned due to strong electron-phonon coupling effect. A mechanism based on the semi-classical longitudinal-optical-phonon-plasmon theory is first proposed to explain the SCTD-induced Raman scattering modulation. Our findings offer a feasible route for modulation of electrical and optical properties of compound semiconductor nanostructures.