Konig, DirkHiller, DanielSmith, Sean2020-06-032020-06-03http://hdl.handle.net/1885/204792Conventional impurity doping of ultrasmall nanoscale silicon (Si) currently used in very-large-scale integration faces serious miniaturization challenges below the 14-nm technology node such as dopant out-diffusion and inactivation by clustering in Si-based field-effect transistors (FETs). For Si nanocrystals showing quantum confinement, self-purification and massively increased ionization energies cause doping to fail. Modulation doping is widely used in group III–group V materials in particular for optoelectronic applications, where high carrier densities at low scattering and nonradiative recombination rates are crucial. Setting out from our recent success to introduce modulation acceptors into SiO2 with aluminum to provide holes to Si [König et al., Sci. Rep. 7, 46703 (2017)], we follow our atomistic concept to investigate other possible modulation acceptors in SiO2. Using density functional theory and experimental verification of key candidates by capacitance-voltage and deep-level-transient-spectroscopy measurements, we elucidate the role of atomistic parameters that determine the ability of the dopant species to provide modulation-acceptor states to SiO2 and thus holes to Si. Modulation-doped SiO2 can replace conventional doping of ultrasmall nanoscale Si from the SiO2 coating or trench of a FET and have a high potential for carrier-selective tunneling contacts in Si-based heterojunction solar cells and tunnel FETs.D.K. thanks J. Rudd for computer-cluster administration and acknowledges use of the Abacus computer cluster, Integrated Materials Design Centre, University of New South Wales, and funding by a 2015 University of New South Wales blue sky research grant and by the 2018 Theodore von Kármán Fellowship of RWTH Aachen University, Germany. D.K. and D.H. acknowledge funding by 2012, 2014, and 2016 DAAD-Go8 joint-researchcooperation schemes. D.H. acknowledges the Alexander von Humboldt Foundation for a Feodor Lynen Fellowship and the German Research Foundation (DFG) for funding (Grant No. HI 1779/3-1).12 pagesapplication/pdfen-AU© 2018 American Physical Society. Dirk König, Daniel Hiller, and Sean Smith, Si O 2 Modulation Doping for Si : Acceptor Candidates, Phys. Rev. Applied 10, 054034 – Published 14 November 2018 doi https://doi.org/10.1103/PhysRevApplied.10.054034Electronic structure, Local density of states, Optoelectronics, Devices, Dielectrics, Doped semiconductors2018-1110.1103/PhysRevApplied.10.0540342019-12-19