학술논문
Memory and Coulomb blockade effects in germanium nanocrystals embedded in amorphous silicon on silicon dioxide.
Document Type
Article
Source
Subject
*NANOCRYSTALS
*GERMANIUM
*HYSTERESIS loop
*QUANTUM tunneling
*COULOMB functions
*OPTOELECTRONIC device design & construction
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Language
ISSN
0021-8979
Abstract
Germanium nanocrystals embedded in amorphous silicon and self-organized on a tunnel silicon dioxide layer thermally grown on (100) p-doped silicon substrate have been electrically studied at different temperatures by using current-voltage and capacitance-voltage measurements. Results showed a carrier exchange between the gate and isolated germanium nanocrystals via amorphous silicon. Hysteresis loops observed in the capacitance-voltage curves were attributed to electron injection/emission process in germanium nanocrystals, which indicated a memory effect behavior. Resonant tunneling effect through germanium nanocrystals with large voltage gaps was observed at room temperature in these ultradense Ge nanocrystals of ∼3.5 nm mean size. It appeared for increasingly low voltages when the temperature decreases. All these results are consistent with a Coulomb blockade effect in ultrasmall Ge nanocrystals in which an effective number of electrons transported by each tunneling step varied between 1.8 and 3.81. [ABSTRACT FROM AUTHOR]