Quick search Find article
Quick search
Find article

Quantum dot networks in dielectric media: from compact modeling of transport to the origin of field effect luminescence

Josep Carreras1, O Jambois1, S Lombardo2,3 and B Garrido1

Show affiliations


We present a compact model of transport through a random distribution of interacting quantum dots embedded in a dielectric matrix. The model is based on a network of interconnected tunnel junctions sandwiched between two electrodes, resulting in a system of nonlinear differential equations which is numerically solved for a given time-dependent voltage applied to the gate. The capacitance matrix, electron/hole tunneling currents and the effective area of conduction between quantum dots are calculated at each integration step. The transport properties obtained from the model are successfully validated against experimental data for a silicon nanocrystal basic MOS cell, showing its potential applicability to non-volatile memories. In addition, through a simple rate equation, the calculated charge flux tunneling or impacting the nanocrystals is converted into electroluminescence. In this regard, we discuss the origin of the recently reported field effect luminescence in silicon nanocrystals. It is found that the idea of quantum-confined exciton creation through sequential injection of opposite sign carriers is in contradiction with the model and with the electron/hole tunneling time ratio obtained through the WKB approximation due to the difference in the electron and hole potential barrier heights. We show how our model of transport, along with a rate equation with the reported value for the absorption cross section for electrical excitation of silicon nanocrystals (~10−14 cm2), is in good agreement with experimental data obtained under pulsed excitation, without requiring further assumptions such as the formation of excitons from hole tunneling into electron-charged nanocrystals, revealing impact excitation of electrons/holes from the same substrate as the physical origin of the observed field effect luminescence.


PACS

78.67.Hc Quantum dots

73.63.Kv Quantum dots

73.40.Gk Tunneling

73.63.Bd Nanocrystalline materials

78.67.Bf Nanocrystals and nanoparticles

78.60.Fi Electroluminescence

Subjects

Condensed matter: electrical, magnetic and optical

Surfaces, interfaces and thin films

Nanoscale science and low-D systems

Dates

Issue 15 (15 April 2009)

Received 2 October 2008, in final form 24 February 2009

Published 24 March 2009



  1. Quantum dot networks in dielectric media: from compact modeling of transport to the origin of field effect luminescence

    Josep Carreras et al 2009 Nanotechnology 20 155201

  2. The size-controlled synthesis of Pd/C catalysts by different solvents for formic acid electrooxidation

    Yunjie Huang et al 2009 Nanotechnology 20 105604

  3. Quantum aspects of semantic analysis and symbolic artificial intelligence

    Diederik Aerts and Marek Czachor 2004 J. Phys. A: Math. Gen. 37 L123

  4. Nanoantenna array-induced fluorescence enhancement and reduced lifetimes

    Reuben M Bakker et al 2008 New J. Phys. 10 125022

  5. Transformation optics: approaching broadband electromagnetic cloaking

    A V Kildishev et al 2008 New J. Phys. 10 115029

  6. Successive Solar Flares and Coronal Mass Ejections on 2005 September 13 from NOAA AR 10808

    Chang Liu et al. 2009 ApJ 703 757

  7. A control approach to high-speed probe-based nanofabrication

    Yan Yan et al 2009 Nanotechnology 20 175301

  8. Room temperature Cl2 sensing using thick nanoporous films of Sb-doped SnO2

    Allen Chaparadza and Shankar B Rananavare 2008 Nanotechnology 19 245501

  9. FOCUS ON NEUTRINO PHYSICS

    Francis Halzen et al 2004 New J. Phys. 6

  10. Magnons in ferromagnetic metallic manganites

    Jiandi Zhang et al 2007 J. Phys.: Condens. Matter 19 315204

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.