Size effect on electronic transport in nC–Si/SiO{sub x} core/shell quantum dots
- Nano-Science Group, Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)
Highlights: ► Electrical conductivity (σ) demonstrated to exhibit quantum size effect for Si-QDs. ► High σ ∼ 4 × 10{sup −2} S cm{sup −1} for Si-QDs of average size ∼3.7 nm, number density ∼4.8 × 10{sup 11} cm{sup −2}. ► Heterojunction-like band-structure at the QD interface controls electronic transport. -- Abstract: Electronic transport in silicon quantum dots (Si-QDs) in core/shell configuration was studied. The nC–Si cores encapsulated by protective SiO{sub x} shells embedded in a-Si matrix were obtained from one-step and spontaneous plasma processing, at low substrate temperature (300 °C) compatible for device fabrication. The size, density and distribution of nC–Si QDs were controlled by optimizing the plasma parameters. Very high electrical conductivity, σ ∼ 4 × 10{sup −2} S cm{sup −1}, was achieved at a total number density of Si-QDs, N ∼ 4.8 × 10{sup 11} cm{sup −2}, corresponding to the lowering in its average core size, d ∼ 3.7 nm, to the order of the bulk Si exciton Bohr radius and the associated quantum confinement effects. The electrical conductivity was demonstrated to exhibit quantum size (3 < d (nm) < 10) effect in zero dimensional quantum dots. The underlying electronic transport was explained using heteroquantum-dot model, the nC–SiO{sub x}:H QDs possess hetero-junction like band structure in the interface regions, due to their different band gaps.
- OSTI ID:
- 22215602
- Journal Information:
- Materials Research Bulletin, Vol. 47, Issue 11; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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