This Presentation will give a glimpse on three major research topics I am working on:

1. Direct modulation doping of Si-based dielectrics, delivering majority charge carriers into adjacent Si, Ge, and SiGe^[1-9].
Doping dielectric layers adjacent to Si removes impediments of conventional Si impurity doping^[10,11]: inelastic Coulomb scattering, thermionic dopant ionization, dopant out-diffusion/segregation/clustering, statistical deviations, the latter two preventing advancement of VLSI miniaturization. Semiconductor NWires featuring unprecedented high carrier mobilities and densities show electric conductivity increase of ≥ 10⁶ when coated with modulation-acceptor (MA)-doped SiO2, exploiting also an associated 80 % decrease in the Schottky barrier at NiSi. No freeze-out of carrier densities occurs; conductivity at T = 300 K is reduced to 46 % at T = 2 K, presenting a game-changer for peripheral qubit electronics. Identified modulation donors in theory and experiment close the circle for complementary logic.

2. The Nanoscale Electronic Structure Shift Induced by Anions at Surfaces (NESSIAS) effect which replaces doping altogether for deep nanoscale (dns) Si, Ge, and C^[12-19].
The NESSIAS effect is generated by SiO₂/Si₃N₄ on Si, working on a scale of 1.5 nm per plane interface. The quantum-chemical nature of SiO₂ (Si₃N₄) increases (lowers) the binding energy of embedded Si, resulting in n-type (p-type) electronic structure ‘landscapes’ which can attract (expel) electrons from (to) metallic interconnects. Eight years cumulative 1200 h beamtime for UPS and XAS-TFY yielded detailed mappings of band structures, corroborated by large-scale high-accuracy hybrid-DFT calculations. NWells of ≤ 2.5 nm thickness, and NWires of ≤ 5 nm diameter would profit tremendously from the NESSIAS; synchrotron data revealed a p/n junction for 1.9 nm Si NWells with band offsets of ca. 0.7 E_gap.

3. Analytic crystallographic-mathematical algorithms, describing exact numbers of atoms (N_NC, N_Wire), internal bonds (N_bnd) and interface bonds (N_IF) of zincblende and diamond (zb/d) nanocrystals (NCs) as well as NWire cross-sections with zb/d or wurtzite (w) structure^[20-30].
Such algorithms allow to describe NCs and NWires with accuracies limited only by experimental image data. Morphing of NWire cross-sections allows to fit any shape of convex-hexagonal NWires, getting exact data on bonds per atom N_bnd/N_Wire, interface bonds per atom, the ratio of interface bonds per internal bond, areas, facet lengths, etc. Simple and core-shell NWire cross-sections can be morphed to arbitrary hexagonal shape, whereby their structural-thermodynamic state space is assessed by N_bnd/N_Wire over main (size) and morphing (shape) run indices in respective number series. Thus, a clear parameter space for optimum (max. stable defect-free) NWire growth exists. All algorithms are useable for any characterization technique, as demonstrated for NC free surface energy, shape detection by ESR, NWire stability, assessment of NESSIAS, and NC segregation and formation phenomena.

Dr Dirk König studied Technical Cybernetics and Solid State Electronics at Chemnitz University of Technology (TUCh), Germany, and University of Hull, GB, before working in solar cell research. Enjoying an accompanying study of solid-state physics at TUCh, he defended his Dr. rer. nat. in solid state physics with Magna Cum Laude in 2004. After a 2-year industrial research position with AMD Europe and TUCh (45 nm node), he obtained a 2-year Toyota Research Fellowship at the ARC-PV-CoE, UNSW, where he headed the theory and characterization groups in the 3rd Generation Strand from 2006. In 2014, he accepted the inaugural position of deputy director of fundamental research and group leader of electronic materials in the IMDC at UNSW under Prof. S.C. Smith. After working as an industrial research consultant for several European companies and institutes, he joined the IMDL at ANU in March 2022 and is now working at MP, RSPhys at ANU. His works can be found at https://www.researchgate.net/profile/D-Koenig-2/research. 

^{[1] https://www.nature.com/articles/srep46703 [2] http://dx.doi.org/10.1021/acsami.8b06098 [3] http://dx.doi.org/10.1103/PhysRevApplied.10.054034 [4] https://doi.org/10.1063/1.5054703 [5] https://doi.org/10.1016/j.solmat.2020.110654 [6] https://doi.org/10.1088/1361-6463/abf675 [7] https://doi.org/10.1002/pssa.202300068 [8] https://doi.org/10.1002/admi.202300600 [9] https://doi.org/10.1002/adfm.202415230 [10] https://www.science.org/doi/10.1126/science.1143802 [11] https://www.nature.com/articles/srep09702 [12] http://dx.doi.org/10.1103/PhysRevB.78.035339 [13] https://doi.org/10.1016/j.solmat.2008.09.026 [14] https://doi.org/10.1002/admi.201400359 [15] https://doi.org/10.3762%2Fbjnano.9.210 [16] http://dx.doi.org/10.1103/PhysRevApplied.12.054050 [17] https://pubs.acs.org/doi/10.1021/acsami.0c22360 [18] https://doi.org/10.1002/apxr.202200065 [19] https://doi.org/10.1002/pssa.202300066 [20] http://dx.doi.org/10.1063/1.4960994 [21] https://doi.org/10.1063/5.0270948 [22] https://doi.org/10.1021/acsnano.4c11376 [23] https://journals.iucr.org/paper?S2052520619009351 [24] https://doi.org/10.1107/S2052520621008015 [25] https://doi.org/10.1107/S2052520622004942 [26] https://doi.org/10.1107/S2052520623000434 [27] https://doi.org/10.1002/adts.202400368 [28] https://doi.org/10.1107/S2052520622004954 [29] https://doi.org/10.1107/S2052520625000873 [30] https://doi.org/10.1002/adts.202400951}