1 / 20

Donor-Acceptor Complexes in ZnO

Donor-Acceptor Complexes in ZnO. M. Türker , M. Deicher , H. Wolf, and Th . Wichert. Universität des Saarlandes Technische Physik, 66123 Saarbrücken. The ISOLDE Collaboration CERN, Geneva , Switzerland. Zinc Oxide. E G = 3.37 eV at RT E exciton binding = 60 meV

xannon
Download Presentation

Donor-Acceptor Complexes in ZnO

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Donor-Acceptor Complexes in ZnO M. Türker, M. Deicher, H. Wolf, andTh. Wichert Universität des Saarlandes Technische Physik, 66123 Saarbrücken The ISOLDE Collaboration CERN, Geneva, Switzerland

  2. Zinc Oxide EG = 3.37 eV at RT Eexcitonbinding = 60 meV Bulk crystal Easy to dope n-type Difficultto dope p-type Zn NO O Bulk crystal c-axis 2

  3. Howtoenhance p-type doping? possible In-N2 complex Donor-AcceptorCodoping Yamamoto andKatayama-Yoshida Physica B 302 (2001) 155 Donor-Acceptor Cluster-Doping Wang andZunger Physical Review Letters 90 (2003) 256401 Zn NO O InZn 3

  4. Howtoenhance p-type doping? increaseby factor1000 possible In-N2 complex Donor-AcceptorCodoping Yamamoto andKatayama-Yoshida Physica B 302 (2001) 155 Donor-Acceptor Cluster-Doping Wang andZunger Physical Review Letters 90 (2003) 256401 Zn NO O ElectricalpropertiesofZnOfilms InZn Chen, Lu, Ye, Lin, Zhao, Ye, Li, andZhu Applied Physics Letters 87 (2005) 252106 3

  5. Codopingwith In and N byimplantation possible In-N2 complex SIMS depthprofiling as implanted TA=1073K t=60min 1020 1019 1018 1017 1016 Zn Concentration[ions/cm3] NO O N In In InZn In In N 0.0 0.4 0.8 1.2 0.0 0.4 0.8 1.2 depth[μm] Park, Sakaguchi, Ohashi, Hishita, andHaneda Applied Surface Science 203-204 (2003) 359 4

  6. Perturbed Angular Correlation (PAC) • Electrical • fieldgradientVij • strengthVzz • symmetryη= • orientation • EFG ~ r – 3 • - microscopiclocal Zn Zn Vxx- Vyy Vzz O O NO 111InZn 111InZn EFGlattice EFGdefect 5

  7. Perturbed Angular Correlation (PAC) 111In Donor-acceptor interaction T1/2 = 3 d EC 1 Observation T1/2 = 85 ns Q 2 111Cd 6

  8. ω2 ω3 ω1 EFG ≠ 0 e Q Vzz 10 Q= w1= 3p h Q: quadrupolecouplingconstant Perturbed Angular Correlation (PAC) 111In Donor-acceptor interaction T1/2 = 3 d EC 1 Observation T1/2 = 85 ns Q 2 111Cd 6

  9. detector detector IntrinsicEFGlatticeofZnO 111In implantation; TA = 1100K tA= 30min R(t) Fourier transforms c-axis: EFGlattice Q= 31MHz  = 0 f = 86% t [ns] w [Mrad/s] 45°-geometry 7

  10. CodopingofZnO Indium penetrationin ZnO 111In implantation; TA = 1100K tA= 30min R(t) Fourier transforms depth974 Å EFGlattice Q= 31MHz  = 0 f = 86% E = 400 keV (atoms/cm3) / (atoms/cm2) In t [ns] w [Mrad/s] depth3368 Å Group V energypenetrationdepth N 220keV 3368Å P 400keV 3179Å As Sb 400keV 1228Å E = 220 keV (atoms/cm3) / (atoms/cm2) N 8

  11. Indium-Nitrogen codopingofZnO N (220keV) + 111In (400keV); TA = 1000K tA= 20min Q2 Q1 FT(ω) R(t) Q2 Q1 FT(ω) R(t) t [ns] w [Mrad/s] 9

  12. Indium-Nitrogen codopingofZnO N (220keV) + 111In (400keV); TA = 1000K tA= 20min Q2 2 axial symmetrical EFGdefect: Q1 FT(ω) R(t) c-axisoriented Q1=209(1)MHz =0 f=2% Q2 Q1 basal plane oriented Q2=234(1)MHz ≤0 f=5% FT(ω) R(t) t [ns] w [Mrad/s] w [Mrad/s] 9

  13. f0 f2 f1 Indium-Nitrogen codopingofZnO Isochronicannealing 10

  14. Indium-PhosphoruscodopingofZnO P (400keV) + 111In (400keV); TA = 800K tA= 60min 2 axial symmetrical EFGdefect: Q2 Q1 FT(ω) R(t) c-axisoriented Q1=153(1)MHz =0 f=2% Q2 Q1 basal plane oriented Q2=176(1)MHz ≤0 f=10% FT(ω) R(t) t [ns] w [Mrad/s] 11

  15. Formation of Indium-Acceptor-Pairs in II-VI semiconductors cubic wurtzite theoretical * Ostheimer, Jost, Filz, Lauer, Wolf, and Wichert Applied Physics Letters 69 (1996) 2840 * * Lany, Ostheimer, Wolf, and Wichert Hyperfine Interactions 136/137 (2001) 619 12

  16. Formation of Indium-Acceptor-Pairs in Zinc Oxide 13

  17. In-N1 In-N2 In-N3 In-N4 Possibleconfigurationsof In-NXComplexes =0 ≤0.1 ≠0 ≠0 ≠0 =0 =0 14

  18. PAC • In-N1: 2 EFG • In-P1: 2 EFG Summary Donor–acceptorcodopingofZnObyionimplantation Aim: analysisofthemicroscopicenvironment on atomiclevel Tool: Perturbed Angular Correlationtoobtainstructuralinformation 15

  19. 77Br Group VII Donor Li Na K Group I Acceptor ISOLDE CERN Work in progress 77Br/ 77Se (60keV); TA = 1100K Q=403 MHz Implantations: Michael Uhrmacher and Daniel Jürgens (U Göttingen) Financial supportbyBMBF 05KK7TS1 16

More Related