Acceptor Modulation Doping of SiO2 for Providing Holes to Si Quantum Dots

Dirk Koenig; James Rudd; Santosh K. Shrestha; Gavin Conibeer; Martin Green

Acceptor Modulation Doping of SiO2 for Providing Holes to Si Quantum Dots

Dirk Koenig^*, James Rudd, Santosh K. Shrestha, Gavin Conibeer, Martin Green

^*Corresponding author for this work

Research output: Contribution to conference › Paper › peer-review

Abstract

The thermodynamics of foreign atoms in nano crystals (NCs) shows that conventional doping is not feasible to a degree required for high quality devices. Modulation doping is used for III-V super lattices (SLs), with excellent results for majority carriers. Adopting modulation doping to Si NCs in a SiO2 matrix is difficult. We investigated -SiO2 approximants by ab-initio methods. Conventional Si dopants fail to deliver shallow energy levels which can be occupied. Finding donors in SiO2 in order to provide electrons for Si NCs is not possible due to the strong anionic nature of oxygen (O). However, scandium (Sc) works as an acceptor when replacing Si. The electronic nature of Sc results in a lowest unoccupied molecular orbital (LUMO) at an unusually high electron affinity (X). This LUMO can then be doubly occupied by accepting an electron from Si NCs. The doping approach does not depend on the NC material.
Keywords: Doping, Quantum Structure, Si, Ge, DFT

Original language	English
Pages	575-578
Number of pages	4
Publication status	Published - 25 Sept 2009
Externally published	Yes
Event	24th European Photovoltaic Solar Energy Conference 2009 - Hamburg, Germany Duration: 21 Sept 2009 → 25 Sept 2009 Conference number: 24

Conference

Conference	24th European Photovoltaic Solar Energy Conference 2009
Abbreviated title	EUPVSEC 2009
Country/Territory	Germany
City	Hamburg
Period	21/09/09 → 25/09/09
Other	September 21-24 2009

Cite this

@conference{a0c2f3b12db8436ebf1c70f6f5c89ca9,

title = "Acceptor Modulation Doping of SiO2 for Providing Holes to Si Quantum Dots",

abstract = "The thermodynamics of foreign atoms in nano crystals (NCs) shows that conventional doping is not feasible to a degree required for high quality devices. Modulation doping is used for III-V super lattices (SLs), with excellent results for majority carriers. Adopting modulation doping to Si NCs in a SiO2 matrix is difficult. We investigated -SiO2 approximants by ab-initio methods. Conventional Si dopants fail to deliver shallow energy levels which can be occupied. Finding donors in SiO2 in order to provide electrons for Si NCs is not possible due to the strong anionic nature of oxygen (O). However, scandium (Sc) works as an acceptor when replacing Si. The electronic nature of Sc results in a lowest unoccupied molecular orbital (LUMO) at an unusually high electron affinity (X). This LUMO can then be doubly occupied by accepting an electron from Si NCs. The doping approach does not depend on the NC material.Keywords: Doping, Quantum Structure, Si, Ge, DFT",

author = "Dirk Koenig and James Rudd and Shrestha, {Santosh K.} and Gavin Conibeer and Martin Green",

year = "2009",

month = sep,

day = "25",

language = "English",

pages = "575--578",

note = "24th European Photovoltaic Solar Energy Conference 2009, EUPVSEC 2009 ; Conference date: 21-09-2009 Through 25-09-2009",

}

TY - CONF

T1 - Acceptor Modulation Doping of SiO2 for Providing Holes to Si Quantum Dots

AU - Koenig, Dirk

AU - Rudd, James

AU - Shrestha, Santosh K.

AU - Conibeer, Gavin

AU - Green, Martin

N1 - Conference code: 24

PY - 2009/9/25

Y1 - 2009/9/25

N2 - The thermodynamics of foreign atoms in nano crystals (NCs) shows that conventional doping is not feasible to a degree required for high quality devices. Modulation doping is used for III-V super lattices (SLs), with excellent results for majority carriers. Adopting modulation doping to Si NCs in a SiO2 matrix is difficult. We investigated -SiO2 approximants by ab-initio methods. Conventional Si dopants fail to deliver shallow energy levels which can be occupied. Finding donors in SiO2 in order to provide electrons for Si NCs is not possible due to the strong anionic nature of oxygen (O). However, scandium (Sc) works as an acceptor when replacing Si. The electronic nature of Sc results in a lowest unoccupied molecular orbital (LUMO) at an unusually high electron affinity (X). This LUMO can then be doubly occupied by accepting an electron from Si NCs. The doping approach does not depend on the NC material.Keywords: Doping, Quantum Structure, Si, Ge, DFT

AB - The thermodynamics of foreign atoms in nano crystals (NCs) shows that conventional doping is not feasible to a degree required for high quality devices. Modulation doping is used for III-V super lattices (SLs), with excellent results for majority carriers. Adopting modulation doping to Si NCs in a SiO2 matrix is difficult. We investigated -SiO2 approximants by ab-initio methods. Conventional Si dopants fail to deliver shallow energy levels which can be occupied. Finding donors in SiO2 in order to provide electrons for Si NCs is not possible due to the strong anionic nature of oxygen (O). However, scandium (Sc) works as an acceptor when replacing Si. The electronic nature of Sc results in a lowest unoccupied molecular orbital (LUMO) at an unusually high electron affinity (X). This LUMO can then be doubly occupied by accepting an electron from Si NCs. The doping approach does not depend on the NC material.Keywords: Doping, Quantum Structure, Si, Ge, DFT

M3 - Paper

SP - 575

EP - 578

T2 - 24th European Photovoltaic Solar Energy Conference 2009

Y2 - 21 September 2009 through 25 September 2009

ER -

Acceptor Modulation Doping of SiO2 for Providing Holes to Si Quantum Dots

Abstract

Conference

Fingerprint

Cite this