Fundamentals of zinc oxide as a semiconductor

In the past ten years we have witnessed a revival of, and subsequent rapid expansion in, the research on zinc oxide (ZnO) as a semiconductor. Being initially considered as a substrate for GaN and related alloys, the availability of high-quality large bulk single crystals, the strong luminescence demonstrated in optically pumped lasers and the prospects of gaining control over its electrical conductivity have led a large number of groups to turn their research for electronic and photonic devices to ZnO in its own right. The high electron mobility, high thermal conductivity, wide and direct band gap and large exciton binding energy make ZnO suitable for a wide range of devices, including transparent thin-film transistors, photodetectors, light-emitting diodes and laser diodes that operate in the blue and ultraviolet region of the spectrum. In spite of the recent rapid developments, controlling the electrical conductivity of ZnO has remained a major challenge. While a number of research groups have reported achieving p-type ZnO, there are still problems concerning the reproducibility of the results and the stability of the p-type conductivity. Even the cause of the commonly observed unintentional n-type conductivity in as-grown ZnO is still under debate. One approach to address these issues consists of growing high-quality single crystalline bulk and thin films in which the concentrations of impurities and intrinsic defects are controlled. In this review we discuss the status of ZnO as a semiconductor. We first discuss the growth of bulk and epitaxial films, growth conditions and their influence on the incorporation of native defects and impurities. We then present the theory of doping and native defects in ZnO based on density-functional calculations, discussing the stability and electronic structure of native point defects and impurities and their influence on the electrical conductivity and optical properties of ZnO. We pay special attention to the possible causes of the unintentional n-type conductivity, emphasize the role of impurities, critically review the current status of p-type doping and address possible routes to controlling the electrical conductivity in ZnO. Finally, we discuss band-gap engineering using MgZnO and CdZnO alloys.

[1]  M. Ferenets,et al.  Thin Solid Films , 2010 .

[2]  M. Teisseire,et al.  (Zn, Mg)O/ZnO-based heterostructures grown by molecular beam epitaxy on sapphire: Polar vs. non-polar , 2009, Microelectron. J..

[3]  J. Sann,et al.  Combinatorial growth of Mgx Zn1–x O epilayers by chemical vapor deposition , 2009 .

[4]  M. Stutzmann,et al.  Optical properties and structural characteristics of ZnMgO grown by plasma assisted molecular beam epitaxy , 2009 .

[5]  C. Freysoldt,et al.  Fully ab initio finite-size corrections for charged-defect supercell calculations. , 2009, Physical review letters.

[6]  M. R. Wagner,et al.  Nitrogen incorporation in homoepitaxial ZnO CVD epilayers , 2009 .

[7]  N. Doltsinis,et al.  Advances in Solid State Physics , 2009 .

[8]  James S. Speck,et al.  Causes of incorrect carrier-type identification in van der Pauw–Hall measurements , 2008 .

[9]  Atsuo Yamada,et al.  Polarization-induced two-dimensional electron gases in ZnMgO/ZnO heterostructures , 2008 .

[10]  Sheng Chu,et al.  Electrically pumped ultraviolet ZnO diode lasers on Si , 2008 .

[11]  N. Ohashi,et al.  Positive Hall coefficients obtained from contact misplacement on evident n-type ZnO films and crystals , 2008 .

[12]  A. Sasaki,et al.  Plasma-assisted Molecular Beam Epitaxy of High Optical Quality MgZnO Films on Zn-polar ZnO Substrates , 2008 .

[13]  Young-Il Kim,et al.  Local structures of polar wurtzites Zn1-xMgxO studied by Raman and 67Zn/25Mg NMR spectroscopies and by total neutron scattering , 2008, 0808.0492.

[14]  S. Denbaars,et al.  Step-flow growth of ZnO(0 0 0 1) on GaN(0 0 0 1) by metalorganic chemical vapor epitaxy , 2008 .

[15]  S. Denbaars,et al.  Metalorganic chemical vapor deposition of ZnO(0001) thin films on GaN(0001) templates and ZnO(0001) substrates , 2008 .

[16]  I. Tanaka,et al.  Defect energetics in ZnO: A hybrid Hartree-Fock density functional study , 2008 .

[17]  W. Lambrecht,et al.  First-principles calculation of the O vacancy in ZnO: A self-consistent gap-corrected approach , 2008 .

[18]  L. J. Mandalapu,et al.  Sb-doped p-ZnO∕Ga-doped n-ZnO homojunction ultraviolet light emitting diodes , 2008 .

[19]  N. Giles,et al.  Further characterization of oxygen vacancies and zinc vacancies in electron-irradiated ZnO , 2008 .

[20]  S. Jokela,et al.  Sources of n-type conductivity in ZnO , 2007 .

[21]  D. Look.  Quantitative analysis of surface donors in ZnO , 2007 .

[22]  A. Janotti,et al.  Native point defects in ZnO , 2007 .

[23]  J. Bläsing,et al.  Homoepitaxial growth of ZnO by metalorganic vapor phase epitaxy in two-dimensional growth mode , 2007 .

[24]  D. Clarke,et al.  Evolution of local structures in polycrystalline Zn 1 − x Mg x O ( 0 ⩽ x ⩽ 0.15 ) studied by Raman spectroscopy and synchrotron x-ray pair-distribution-function analysis , 2007 .

[25]  D. Look,et al.  Electron and Hole Traps in N-Doped ZnO Grown on p-Type Si by Metalorganic Chemical Vapor Deposition , 2007 .

[26]  J. Sann,et al.  Homoepitaxy of ZnO: from the substrates to doping , 2007 .

[27]  J. Sann,et al.  On the role of group I elements in ZnO , 2007 .

[28]  A. Waag,et al.  H2O2-molecular beam epitaxy of high quality ZnO , 2007 .

[29]  J. Sann,et al.  Properties of the oxygen vacancy in ZnO , 2007 .

[30]  Jingbo Li,et al.  Possible approach to overcome the doping asymmetry in wideband gap semiconductors. , 2007, Physical review letters.

[31]  A. Janotti,et al.  Absolute deformation potentials and band alignment of wurtzite ZnO, MgO, and CdO , 2007 .

[32]  Masashi Kawasaki,et al.  Quantum Hall Effect in Polar Oxide Heterostructures , 2007, Science.

[33]  Y. Gu,et al.  Study on anomalous high p-type conductivity in ZnO films on silicon substrate prepared by ultrasonic spray pyrolysis , 2007 .

[34]  J. Bläsing,et al.  Preparation of ZnO substrates for epitaxy: Structural, surface, and electrical properties , 2007 .

[35]  A. Zunger,et al.  Dopability, intrinsic conductivity, and nonstoichiometry of transparent conducting oxides. , 2007, Physical review letters.

[36]  Young-Il Kim,et al.  Synchrotron X-ray study of polycrystalline wurtzite Zn1−xMgxO (0 ≤ x ≤ 0.15): Evolution of crystal structure and polarization , 2006, cond-mat/0611419.

[37]  Yujia Zeng,et al.  Identification of acceptor states in Li-doped p-type ZnO thin films , 2006 .

[38]  Anderson Janotti,et al.  Effects of cation d states on the structural and electronic properties of III-nitride and II-oxide wide-band-gap semiconductors , 2006 .

[39]  Shengbai Zhang,et al.  p-type behavior in nominally undoped ZnO thin films by oxygen plasma growth , 2006 .

[40]  Jörg Neugebauer,et al.  HYDROGEN IN SEMICONDUCTORS , 2006 .

[41]  P. Briddon,et al.  First-principles study of the diffusion of hydrogen in ZnO. , 2006, Physical review letters.

[42]  Sang-Jun Cho,et al.  Thermal conductivity of bulk ZnO after different thermal treatments , 2006 .

[43]  Kee-Joo Chang,et al.  P-type doping with group-I elements and hydrogenation effect in ZnO , 2006 .

[44]  Paul Erhart,et al.  First-principles study of migration mechanisms and diffusion of oxygen in zinc oxide , 2006 .

[45]  P. Günter,et al.  Characterization of second and third order optical nonlinearities of ZnO sputtered films , 2006 .

[46]  L. J. Mandalapu,et al.  Homojunction photodiodes based on Sb-doped p-type ZnO for ultraviolet detection , 2006 .

[47]  J. Tominaga,et al.  Direct observation of nitrogen location in molecular beam epitaxy grown nitrogen-doped ZnO. , 2006, Physical review letters.

[48]  Joongoo Kang,et al.  Defect properties and p -type doping efficiency in phosphorus-doped ZnO , 2006 .

[49]  A. Janotti,et al.  New insights into the role of native point defects in ZnO , 2006 .

[50]  S. Pearton,et al.  Zinc oxide bulk, thin films and nanostructures : processing, properties and applications , 2006 .

[51]  W. Eccleston,et al.  Mater. Res. Soc. Symp. Proc. , 2006 .

[52]  Mehul C. Raval,et al.  solar cells , 2007 .

[53]  A. Waag,et al.  Analysis of a conducting channel at the native zinc oxide surface , 2006 .

[54]  S. Pearton,et al.  Hydrogen local modes and shallow donors in ZnO , 2005 .

[55]  D. Look,et al.  Evidence for native-defect donors in n-type ZnO. , 2005, Physical review letters.

[56]  P. Kiesel,et al.  Effects of an Electrically Conducting Layer at the Zinc Oxide Surface , 2005 .

[57]  L. J. Mandalapu,et al.  High-mobility Sb-doped p-type ZnO by molecular-beam epitaxy , 2005 .

[58]  David P. Norton,et al.  Origin of green luminescence in ZnO thin film grown by molecular-beam epitaxy , 2005 .

[59]  A. Janotti,et al.  Oxygen vacancies in ZnO , 2005 .

[60]  S. Jokela,et al.  Structure and stability of O-H donors in ZnO from high-pressure and infrared spectroscopy , 2005 .

[61]  H. Morkoç,et al.  A COMPREHENSIVE REVIEW OF ZNO MATERIALS AND DEVICES , 2005 .

[62]  P. Erhart,et al.  First-principles study of the structure and stability of oxygen defects in zinc oxide , 2005 .

[63]  David C. Look,et al.  Introduction and recovery of point defects in electron-irradiated ZnO , 2005 .

[64]  G. D. Watkins,et al.  Optical detection of electron paramagnetic resonance for intrinsic defects produced in ZnO by 2.5-MeV electron irradiation in situ at 4.2 K , 2005 .

[65]  S. Zhang,et al.  Substitutional diatomic molecules NO, NC, CO, N2, and O2: Their vibrational frequencies and effects on p doping of ZnO , 2005 .

[66]  Patrick R. Briddon,et al.  Theory of Li in ZnO: A limitation for Li-based p -type doping , 2005 .

[67]  Mitsuru Sato,et al.  Growth of 2 inch ZnO bulk single crystal by the hydrothermal method , 2005 .

[68]  J. Nause,et al.  Pressurized melt growth of ZnO boules , 2005 .

[69]  G. D. Watkins,et al.  Optical detection of electron paramagnetic resonance in room-temperature electron-irradiated ZnO , 2005 .

[70]  Akira Ohtomo,et al.  Pulsed laser deposition of thin films and superlattices based on ZnO , 2005 .

[71]  A. Zunger,et al.  Anion vacancies as a source of persistent photoconductivity in II-VI and chalcopyrite semiconductors , 2005, cond-mat/0503018.

[72]  R. Nieminen,et al.  Density-functional calculations of defect formation energies using supercell methods: Defects in diamond , 2005 .

[73]  N. Nickel,et al.  Zinc oxide - a material for micro- and optoelectronic applications , 2005 .

[74]  S. Ogale.  Thin films and heterostructures for oxide electronics , 2005 .

[75]  H. Ohno,et al.  Repeated temperature modulation epitaxy for p-type doping and light-emitting diode based on ZnO , 2004 .

[76]  J. Bläsing,et al.  Heteroepitaxy and nitrogen doping of high-quality ZnO , 2004 .

[77]  H. Ohta,et al.  Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors , 2004, Nature.

[78]  K. Chang,et al.  Possible p-type doping with group-I elements in ZnO , 2004 .

[79]  David C. Look,et al.  Irradiation‐induced defects in ZnO studied by positron annihilation spectroscopy , 2004 .

[80]  A. Waag,et al.  ZnMgO epilayers and ZnO–ZnMgO quantum wells for optoelectronic applications in the blue and UV spectral region , 2004 .

[81]  David C. Look,et al.  Radiation Hardness of ZnO at Low Temperatures , 2004 .

[82]  San-Yuan Chen,et al.  Properties of nitrogen-implanted p-type ZnO films grown on Si3N4/Si by radio-frequency magnetron sputtering , 2004 .

[83]  R. Hoffman.  ZnO-channel thin-film transistors: Channel mobility , 2004 .

[84]  X. M. Li,et al.  Synthesis and characterization of two-layer-structured ZnO p-n homojunctions by ultrasonic spray pyrolysis , 2004 .

[85]  S. Pearton,et al.  Recent advances in processing of ZnO , 2004 .

[86]  D. C. Reynolds,et al.  High-Quality, Melt-Grown ZnO Single Crystals , 2004 .

[87]  Li-ping Zhu,et al.  Low-pressure MOCVD growth of p-type ZnO thin films by using NO as the dopant source , 2004 .

[88]  F. Zhuge,et al.  Preparation of p-type ZnO films by Al+N-codoping method , 2004 .

[89]  C. H. Park,et al.  Doping by large-size-mismatched impurities: the microscopic origin of arsenic- or antimony-doped p-type zinc oxide. , 2004, Physical review letters.

[90]  C. Walle,et al.  First-principles calculations for defects and impurities: Applications to III-nitrides , 2004 .

[91]  G. D. Watkins,et al.  Defects produced in ZnO by 2.5-MeV electron irradiation at 4.2 K: Study by optical detection of electron paramagnetic resonance , 2004 .

[92]  A. Janotti,et al.  Solute diffusion in metals: larger atoms can move faster. , 2004, Physical review letters.

[93]  Jürgen Christen,et al.  Bound exciton and donor–acceptor pair recombinations in ZnO , 2004 .

[94]  Chris G. Van de Walle,et al.  Diffusivity of native defects in GaN , 2004 .

[95]  Mitsuru Sato,et al.  Growth of the 2-in-size bulk ZnO single crystals by the hydrothermal method , 2004 .

[96]  P. Schuck,et al.  Extended RPA with ground-state correlations , 2003, nucl-th/0311016.

[97]  Bruno K. Meyer,et al.  Oxygen vacancies in ZnO , 2003 .

[98]  Kun Liu,et al.  p-Type ZnO thin films prepared by oxidation of Zn3N2 thin films deposited by DC magnetron sputtering , 2003 .

[99]  D. Look,et al.  Evidence of the Zn vacancy acting as the dominant acceptor in n-type ZnO. , 2003, Physical review letters.

[100]  Alexandre Boyer,et al.  Electrical properties of zinc oxide sputtered thin films , 2003, Microelectron. J..

[101]  R. Kling,et al.  Optical and structural analysis of ZnCdO layers grown by metalorganic vapor-phase epitaxy , 2003 .

[102]  H. Koinuma,et al.  Layer-by-layer growth of high-optical-quality ZnO film on atomically smooth and lattice relaxed ZnO buffer layer , 2003 .

[103]  Dali Liu,et al.  Epitaxial growth of NH3-doped ZnO thin films on 〈〉 oriented sapphire substrates , 2003 .

[104]  D. Hwang,et al.  Effects of RF power variation on properties of ZnO thin films and electrical properties of p-n homojunction , 2003 .

[105]  Hyun-Sik Kim,et al.  Realization of p-type ZnO thin films via phosphorus doping and thermal activation of the dopant , 2003 .

[106]  T. S. Lee,et al.  Properties of arsenic-doped p-type ZnO grown by hybrid beam deposition , 2003 .

[107]  Kun Liu,et al.  Fabrication and characterization of p-type ZnO films by pyrolysis of zinc-acetate–ammonia solution , 2003 .

[108]  Z. Ye,et al.  Preparation and characteristics of p-type ZnO films by DC reactive magnetron sputtering , 2003 .

[109]  Ye Zhizhen,et al.  Structural, optical and electrical properties of ZnO thin films prepared by reactive deposition , 2003 .

[110]  Tuomas Pensala,et al.  Piezoelectric ZnO films by r.f. sputtering , 2003 .

[111]  Benjamin J. Norris,et al.  ZnO-based transparent thin-film transistors , 2003 .

[112]  J. Perrière,et al.  Epitaxial growth of ZnO films , 2003 .

[113]  S. Jokela,et al.  Infrared Spectroscopy of Hydrogen in ZnO , 2002 .

[114]  D. C. Reynolds,et al.  Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy , 2002 .

[115]  Suhuai Wei,et al.  Origin of p -type doping difficulty in ZnO: The impurity perspective , 2002 .

[116]  D. C. Reynolds,et al.  Production of nitrogen acceptors in ZnO by thermal annealing , 2002 .

[117]  D. Look,et al.  High spatial resolution thermal conductivity of bulk ZnO (0001) , 2002 .

[118]  Frank Henecker,et al.  Hydrogen: a relevant shallow donor in zinc oxide. , 2002, Physical review letters.

[119]  Andreas Waag,et al.  Donor–acceptor pair transitions in ZnO substrate material , 2001 .

[120]  D. Look,et al.  Magnetic resonance studies of ZnO , 2001 .

[121]  Chris G. Van de Walle,et al.  Defect analysis and engineering in ZnO , 2001 .

[122]  Kee-Joo Chang,et al.  Compensation mechanism for N acceptors in ZnO , 2001 .

[123]  Bixia Lin,et al.  Green luminescent center in undoped zinc oxide films deposited on silicon substrates , 2001 .

[124]  Chunhui Huang,et al.  Room temperature UV emission of MgxZn1−xO films , 2001 .

[125]  B. Meyer,et al.  The Oxygen Vacancy as the Origin of a Green Emission in Undoped ZnO , 2001 .

[126]  Seiji Isotani,et al.  Energetics of native defects in ZnO , 2001 .

[127]  S T Pantelides,et al.  Control of doping by impurity Cchemical potentials: predictions for p-type ZnO. , 2001, Physical review letters.

[128]  Jörg Neugebauer,et al.  First-principles studies of beryllium doping of GaN , 2001 .

[129]  Yiying Wu,et al.  Room-Temperature Ultraviolet Nanowire Nanolasers , 2001, Science.

[130]  K. Stokbro,et al.  Hole trapping at Al impurities in silica: a challenge for density functional theories. , 2001, Physical review letters.

[131]  David C. Look,et al.  Recent Advances in ZnO Materials and Devices , 2001 .

[132]  S. Irvine,et al.  Experimental confirmation of the predicted shallow donor hydrogen state in zinc oxide. , 2001, Physical review letters.

[133]  T. Kawai,et al.  Fabrication and Optoelectronic Properties of a Transparent ZnO Homostructural Light-Emitting Diode , 2001 .

[134]  Akira Ohtomo,et al.  Band gap engineering based on MgxZn1−xO and CdyZn1−yO ternary alloy films , 2001 .

[135]  Tomoji Kawai,et al.  Pulsed laser reactive deposition of p-type ZnO film enhanced by an electron cyclotron resonance source , 2001 .

[136]  A. Zunger,et al.  Intrinsic n-type versus p-type doping asymmetry and the defect physics of ZnO , 2001 .

[137]  Shengbai Zhang,et al.  The thermodynamics of codoping: how does it work? , 2001 .

[138]  David C. Look,et al.  Ga-Doped ZnO Films Grown on GaN Templates by Plasma-Assisted Molecular-Beam Epitaxy , 2000 .

[139]  Y. Ryu,et al.  Fabrication of homostructural ZnO p-n junctions , 2000 .

[140]  Zikang Tang,et al.  Room-temperature stimulated emission of excitons in ZnO/(Mg, Zn)O superlattices , 2000 .

[141]  V. Walle,et al.  Hydrogen as a cause of doping in zinc oxide , 2000 .

[142]  H. R. Chandrasekhar,et al.  Optical and structural properties of ZnO films deposited on GaAs by pulsed laser deposition , 2000 .

[143]  David C. Look,et al.  Synthesis of p-type ZnO films , 2000 .

[144]  G. Ceder,et al.  First-principles study of native point defects in ZnO , 2000 .

[145]  Toru Aoki,et al.  ZnO diode fabricated by excimer-laser doping , 2000 .

[146]  S. Nakamura,et al.  Introduction to Nitride Semiconductor Blue Lasers and Light Emitting Diodes , 2000 .

[147]  K. Sakurai,et al.  Effects of oxygen plasma condition on MBE growth of ZnO , 2000 .

[148]  T. Mason,et al.  Zinc self-diffusion, electrical properties, and defect structure of undoped, single crystal zinc oxide , 2000 .

[149]  M. Glicksman.  Diffusion in solids : field theory, solid-state principles, applications , 2000 .

[150]  H. Funakubo,et al.  Orientation Control of ZnO Thin Film Prepared by CVD , 1999 .

[151]  Tomoji Kawai,et al.  p-Type Electrical Conduction in ZnO Thin Films by Ga and N Codoping , 1999 .

[152]  M. Miki-Yoshida,et al.  Growth, structure and optical characterization of high quality ZnO thin films obtained by spray pyrolysis , 1999 .

[153]  D. C. Reynolds,et al.  Valence-Band Ordering in ZnO , 1999 .

[154]  D. Look,et al.  Residual Native Shallow Donor in ZnO , 1999 .

[155]  Robert P. H. Chang,et al.  Random laser action in semiconductor powder , 1999 .

[156]  Hiroshi Katayama-Yoshida,et al.  Solution Using a Codoping Method to Unipolarity for the Fabrication of p-Type ZnO , 1999 .

[157]  W. Harrison.  Elementary Electronic Structure , 1999 .

[158]  Chris G. Van de Walle,et al.  Chapter 4 Hydrogen in III-V Nitrides , 1999 .

[159]  P. Mooney.  Chapter 2 Defect Identification Using Capacitance Spectroscopy , 1999 .

[160]  Takafumi Yao,et al.  Plasma assisted molecular beam epitaxy of ZnO on c -plane sapphire: Growth and characterization , 1998 .

[161]  S. Studenikin,et al.  Fabrication of green and orange photoluminescent, undoped ZnO films using spray pyrolysis , 1998 .

[162]  G. D. Watkins,et al.  Optically Induced Migration of Interstitial Zinc in ZnSe: Caught in the Act , 1998 .

[163]  Johannes G.E. Gardeniers,et al.  Preferred orientation and piezoelectricity in sputtered ZnO films , 1998 .

[164]  Akira Ohtomo,et al.  MgxZn1−xO as a II–VI widegap semiconductor alloy , 1998 .

[165]  David R. Clarke,et al.  On the optical band gap of zinc oxide , 1998 .

[166]  D. C. Reynolds,et al.  Source of the yellow luminescence band in GaN grown by gas-source molecular beam epitaxy and the green luminescence band in single crystal ZnO , 1998 .

[167]  D. C. Reynolds,et al.  Electrical properties of bulk ZnO , 1998 .

[168]  Theodore D. Moustakas,et al.  Gallium nitride (GaN) , 1998 .

[169]  Michael Stavola,et al.  Identification of defects in semiconductors , 1998 .

[170]  Koji Yano,et al.  Growth of p-type Zinc Oxide Films by Chemical Vapor Deposition , 1997 .

[171]  C. P. Flynn,et al.  Titanium thin film growth on small and large misfit substrates , 1997 .

[172]  S. Myong,et al.  Extremely Transparent and Conductive ZnO:Al Thin Films Prepared by Photo-Assisted Metalorganic Chemical Vapor Deposition (photo-MOCVD) Using AlCl3(6H2O) as New Doping Material , 1997 .

[173]  William L. Warren,et al.  Green photoluminescence efficiency and free-carrier density in ZnO phosphor powders prepared by spray pyrolysis , 1997 .

[174]  K. Lim,et al.  HIGHLY TEXTURED AND CONDUCTIVE UNDOPED ZNO FILM USING HYDROGEN POST-TREATMENT , 1997 .

[175]  C. Walle,et al.  Small valence-band offsets at GaN/InGaN heterojunctions , 1997 .

[176]  D. C. Reynolds,et al.  Similarities in the bandedge and deep-centre photoluminescence mechanisms of ZnO and GaN , 1997 .

[177]  T. Sekiguchi,et al.  Effect of Hydrogenation on ZnO Luminescence , 1997 .

[178]  Modeeparampil N. Kamalasanan,et al.  Sol-gel synthesis of ZnO thin films , 1996 .

[179]  H. Ardakani.  Electrical conductivity of in situ “hydrogen-reduced” and structural properties of zinc oxide thin films deposited in different ambients by pulsed excimer laser ablation , 1996 .

[180]  D. C. Reynolds,et al.  Optically pumped ultraviolet lasing from ZnO , 1996 .

[181]  Jörg Neugebauer,et al.  Gallium vacancies and the yellow luminescence in GaN , 1996 .

[182]  Bruce E. Gnade,et al.  Mechanisms behind green photoluminescence in ZnO phosphor powders , 1996 .

[183]  Jörg Neugebauer,et al.  Role of hydrogen in doping of GaN , 1996 .

[184]  W. C. Hughes,et al.  MBE growth and properties of ZnO on sapphire and SiC substrates , 1996 .

[185]  P. Y. Yu,et al.  Fundamentals of Semiconductors , 1995 .

[186]  Klaus Reimann,et al.  Band gaps, crystal-field splitting, spin-orbit coupling, and exciton binding energies in ZnO under hydrostatic pressure , 1995 .

[187]  Payne,et al.  Periodic boundary conditions in ab initio calculations. , 1995, Physical review. B, Condensed matter.

[188]  K. Tarkpea,et al.  EPR of [FA]0 centres in zinc chalcogenides , 1994 .

[189]  Van de Walle CG,et al.  Atomic geometry and electronic structure of native defects in GaN. , 1994, Physical review. B, Condensed matter.

[190]  M. Nishitani,et al.  Enhanced conductivity of zinc oxide thin films by ion implantation of hydrogen atoms , 1994 .

[191]  Pantelides,et al.  First-principles calculations of solubilities and doping limits: Li, Na, and N in ZnSe. , 1993, Physical review. B, Condensed matter.

[192]  R. Gordon,et al.  Atmospheric pressure chemical vapor deposition of gallium doped zinc oxide thin films from diethyl zinc, water, and triethyl gallium , 1992 .

[193]  Pantelides,et al.  Native defects and self-compensation in ZnSe. , 1992, Physical review. B, Condensed matter.

[194]  Jianhua Hu,et al.  Textured aluminum‐doped zinc oxide thin films from atmospheric pressure chemical‐vapor deposition , 1992 .

[195]  R. Gordon,et al.  Electrical and Optical Properties of Indium Doped Zinc Oxide Films Prepared by Atmospheric Pressure Chemical Vapor Deposition , 1992 .

[196]  D. Chadi.  Column V acceptors in ZnSe: Theory and experiment , 1991 .

[197]  W. W. Wenas,et al.  Electrical and optical properties of boron‐doped ZnO thin films for solar cells grown by metalorganic chemical vapor deposition , 1991 .

[198]  Mengyan Shen,et al.  Optically pumped lasing of ZnO at room temperature , 1991 .

[199]  R. Gordon,et al.  Textured fluorine-doped ZnO films by atmospheric pressure chemical vapor deposition and their use in amorphous silicon solar cells , 1991 .

[200]  A. Pöppl,et al.  ESR and photo-ESR investigations of the V0+ centre in ZnO raw material and Li-doped ZnO ceramic powder , 1990 .

[201]  Berkowitz,et al.  Bands versus bonds in electronic-structure theory of metal oxides: Application to luminescence of copper in zinc oxide. , 1990, Physical review. B, Condensed matter.

[202]  K. Eda,et al.  Zinc oxide varistors , 1989, IEEE Electrical Insulation Magazine.

[203]  A. Pöppl,et al.  ESR Investigation of the Oxygen Vacancy in Pure and Bi203-Doped ZnO Ceramics , 1989, September 16.

[204]  Van de Walle CG,et al.  "Absolute" deformation potentials: Formulation and ab initio calculations for semiconductors. , 1989, Physical review letters.

[205]  Nichols,et al.  Mechanisms of equilibrium and nonequilibrium diffusion of dopants in silicon. , 1989, Physical review letters.

[206]  Van de Walle Cg.  Band lineups and deformation potentials in the model-solid theory. , 1989 .

[207]  S. Z. Weisz,et al.  Low energy hydrogen-ion implantation on thermally treated ZnO surfaces , 1986 .

[208]  S. Pantelides.  Deep centers in semiconductors : a state of the art approach , 1986 .

[209]  B. Hamilton,et al.  Book Review: Point Defects in Semiconductors I: Theoretical Aspects, Point Defects in Semiconductors II: Experimental Aspects , 1984 .

[210]  O. Sankey,et al.  Deep energy levels of defects in the wurtzite semiconductors AIN, CdS, CdSe, ZnS, and ZnO , 1983 .

[211]  A. Hervé,et al.  Optically detected magnetic resonance and optically detected ENDOR of shallow indium donors in ZnO , 1982 .

[212]  M. Lannoo,et al.  Point Defects in Semiconductors II , 1981 .

[213]  E. Kaldis.  Current Topics in Materials Science , 1980 .

[214]  Akira Kawabata,et al.  Characterization of ZnO piezoelectric films prepared by rf planar‐magnetron sputtering , 1980 .

[215]  John Aurie Dean,et al.  Lange's Handbook of Chemistry , 1978 .

[216]  V. Soriano,et al.  Photosensitivity of the EPR spectrum of the F+ center in ZnO , 1976 .

[217]  G. Muller.  Optical and Electrical Spectroscopy of Zinc Oxide Crystals Simultaneously Doped with Copper and Donors , 1976 .

[218]  K. Hagemark.  Defect structure of Zn-doped ZnO , 1976 .

[219]  A. Hervé,et al.  Interactions hyperfines du centre F+ dans ZnO , 1975 .

[220]  A. Hausmann,et al.  Sauerstofflücken als Donatoren in Zinkoxid , 1975 .

[221]  K. Hoffmann,et al.  Electron Spin Resonance of Lattice Defects in Zinc Oxide , 1974 .

[222]  A. Hervé,et al.  Temperature dependence of the ESR spectrum of the zinc vacancy in ZnO , 1974 .

[223]  A. Hausmann,et al.  Halleffekt-messungen an reinen und kupfer dotierten zinkoxidkristallen , 1973 .

[224]  N. Nachtrieb,et al.  The chemistry of imperfect crystals , 1973 .

[225]  R. Lauer.  The I.R. photoluminescence emission band in ZnO , 1973 .

[226]  T. Mookherji.  Electron spin resonance of ultraviolet radiation induced defects in ZnO thermal control coating pigment. , 1972 .

[227]  R. Helbig.  Über die züchtung von grösseren reinen und dotierten ZnO-kristallen aus der gasphase , 1972 .

[228]  A. Scharmann,et al.  EPR investigations on X‐ray and photo‐induced processes in ZnO coating material , 1971 .

[229]  G. D. Watkins,et al.  Radiation effects in semiconductors , 1971 .

[230]  A. Hervé,et al.  ESR spectra of the zinc vacancy in ZnO , 1970 .

[231]  G. Filipovich,et al.  Electron paramagnetic resonance associated with Zn vacancies in neutron-irradiated ZnO , 1970 .

[232]  K. Sancier.  ESR investigation of photodamage to zinc oxide powders , 1970 .

[233]  J. Smith,et al.  ESR of electron irradiated ZnO confirmation of the F + center , 1970 .

[234]  A. Hausmann.  Ein „F-Zentrum” als paramagnetischer Donator in Zinkoxid , 1970 .

[235]  R. Dingle.  Luminescent Transitions Associated With Divalent Copper Impurities and the Green Emission from Semiconducting Zinc Oxide , 1969 .

[236]  O. Schirmer.  The structure of the paramagnetic lithium center in zinc oxide and beryllium oxide , 1968 .

[237]  E. M. Dodson,et al.  Vapour growth of single-crystal zinc oxide , 1968 .

[238]  A. Shepherd,et al.  Semiconductors , 1967, Nature.

[239]  R. Lal,et al.  Electron Paramagnetic Resonance of Photosensitive Donors in ZnO , 1966 .

[240]  C. Geisler,et al.  High temperature induced EPR signals in zinc oxide , 1964 .

[241]  E. D. Kolb,et al.  Hydrothermal Growth of Large Sound Crystals of Zinc Oxide , 1964 .

[242]  A. Yariv,et al.  Electronic Structure of Copper Impurities in ZnO , 1963 .

[243]  P. H. Kasai,et al.  Electron Spin Resonance Studies of Donors and Acceptors in ZnO , 1963 .

[244]  J. Schneider,et al.  Conduction electron spin resonance in group II–VI semiconductors and phosphors , 1963 .

[245]  L. Azároff,et al.  Electron Density Distributions in ZnO Crystals , 1961 .

[246]  J. Schneider,et al.  Notizen: Paramagnetische Resonanz von Donatoren in Zinkoxyd , 1961 .

[247]  J. J. Lander.  Reactions of Lithium as a donor and an acceptor in ZnO , 1960 .

[248]  D. G. Thomas.  The exciton spectrum of zinc oxide , 1960 .

[249]  A. Ballman,et al.  HYDROTHERMAL SYNTHESIS OF ZINC OXIDE AND ZINC SULFIDE1 , 1960 .

[250]  G. Heiland,et al.  Electronic Processes in Zinc Oxide , 1959 .

[251]  D. G. Thomas,et al.  Hydrogen as a Donor in Zinc Oxide , 1956, Halbleiter und Phosphore.

[252]  A. R. Hutson.  Hall Effect Studies of Doped Zinc Oxide Single Crystals , 1957 .

[253]  J. J. Lander.  Concentration of Hydrogen and semi-conductivity in ZnO under hydrogen-ion bombardment , 1957 .

[254]  D. G. Thomas.  Interstitial zinc in zinc oxide , 1957 .

[255]  G. Vineyard.  Frequency factors and isotope effects in solid state rate processes , 1957 .

[256]  E. Mollwo.  Die Wirkung von Wasserstoff auf die Leitfähigkeit und Lumineszenz von Zinkoxydkristallen , 1954 .

[257]  F. A. Kröger,et al.  The Origin of the Fluorescence in Self‐Activated ZnS, CdS, and ZnO , 1954 .

[258]  S. E. Harrison.  Conductivity and Hall Effect of ZnO at Low Temperatures , 1954 .

[259]  C. Kittel.  Introduction to solid state physics , 1954 .

[260]  H. A. Liebhafsky,et al.  X-Ray Absorption , 1949 .