skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Size effect on electronic transport in nC–Si/SiO{sub x} core/shell quantum dots

Abstract

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{submore » x}:H QDs possess hetero-junction like band structure in the interface regions, due to their different band gaps.« less

Authors:
 [1];  [1]
  1. Nano-Science Group, Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)
Publication Date:
OSTI Identifier:
22215602
Resource Type:
Journal Article
Journal Name:
Materials Research Bulletin
Additional Journal Information:
Journal Volume: 47; Journal 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); Journal ID: ISSN 0025-5408
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CONTROL; DEPOSITION; ELECTRIC CONDUCTIVITY; QUANTUM DOTS; SEMICONDUCTOR MATERIALS; SUBSTRATES; THIN FILMS

Citation Formats

Das, Debajyoti, E-mail: erdd@iacs.res.in, and Samanta, Arup. Size effect on electronic transport in nC–Si/SiO{sub x} core/shell quantum dots. United States: N. p., 2012. Web. doi:10.1016/J.MATERRESBULL.2012.06.051.
Das, Debajyoti, E-mail: erdd@iacs.res.in, & Samanta, Arup. Size effect on electronic transport in nC–Si/SiO{sub x} core/shell quantum dots. United States. doi:10.1016/J.MATERRESBULL.2012.06.051.
Das, Debajyoti, E-mail: erdd@iacs.res.in, and Samanta, Arup. Thu . "Size effect on electronic transport in nC–Si/SiO{sub x} core/shell quantum dots". United States. doi:10.1016/J.MATERRESBULL.2012.06.051.
@article{osti_22215602,
title = {Size effect on electronic transport in nC–Si/SiO{sub x} core/shell quantum dots},
author = {Das, Debajyoti, E-mail: erdd@iacs.res.in and Samanta, Arup},
abstractNote = {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.},
doi = {10.1016/J.MATERRESBULL.2012.06.051},
journal = {Materials Research Bulletin},
issn = {0025-5408},
number = 11,
volume = 47,
place = {United States},
year = {2012},
month = {11}
}