Size and Bandgap Control in the Solution-Phase Synthesis of Near-Infrared-Emitting Germanium Nanocrystals

作者：Ruddy Daniel A; Johnson Justin C; Smith E Ryan; Neale Nathan R^*

来源：ACS Nano, 2010, 4(12): 7459-7466.

DOI：10.1021/nn102728u

• germanium nanocrystal
• quantum confinement
• bandgap control
• size control
• mechanism
• infrared emission

We present a novel colloidal synthesis of alkyl-terminated Ge nanoaystals based on the reduction of GeI(4)/GeI(2) mixtures. The size of the nanocrystals (2.3-11.3 nm) was controlled by adjusting both the Ge(IV)/Ge(II) ratio and the temperature ramp rate following reductant injection. The near-infrared absorption (1.6-0.70 eV) and corresponding band-edge emission demonstrate the highly tunable quantum confinement effects in Ge nanocrystals prepared using this mixed-valence precursor method. A mechanism is proposed for the observed size control, which relies upon the difference in reduction temperatures for Ge(II) versus Ge(IV).

• 出版日期2010-12