Size-dependent tunneling differential conductance spectra of crystalline Pd nanoparticles

作者：Wang, B; Wang, KD; Lu, W; Yang, JL; Hou, JG^*

来源：Physical Review B, 2004, 70(20): 205411.

DOI：10.1103/PhysRevB.70.205411

• NANOCRYSTAL QUANTUM DOTS
• DISCRETE ELECTRONIC STATES
• QUASI-PARTICLE LIFETIME
• SINGLE METAL PARTICLES
• ENERGY-LEVELS
• SPECTROSCOPY
• SYSTEM
• MOLECULES
• DYNAMICS
• VOLTAGE

The single-electron tunneling behavior of crystalline palladium nanoparticles with narrowly distributed core sizes ranging from 1.6 to 4 nm is studied by scanning tunneling microscopy/spectroscopy. The current-voltage (I-V) characteristics of Pd nanoparticles exhibit size-dependent fine features, which are assigned to the discreteness of energy states of the ultrasmall Pd particles. It is found that the peak widths, as well as the intrapeak spacings in differential conductance dI/dV spectra increase with the decrease of the size of Pd nanoparticles. Our analysis shows that the dwell time of the weak tunnel junction may not be a major contribution to the peak widths due to the large resistance of the tunnel junction of about 10(7)Omega. The possible effect of residual charge is also excluded. An explanation of the size-dependent behaviors of the peak width and the intrapeak spacing is attributed to the clustered electronic structures around the Fermi level due to certain size-dependent dynamic effects.

• 出版日期2004-11
• 单位中国科学技术大学