P‐type doping and devices based on ZnO

Both n-type and p-type ZnO will be required for development of homojunction light-emitting diodes (LEDs) and laser diodes (LDs). It is easy to obtain strong n-type ZnO, but very difficult to create consistent, reliable, high-conductivity p-type material. The most natural choice of an acceptor dopant is N, substituting for O, and indeed several groups have been able to obtain p-type material by such doping. Surprisingly, however, other groups have also been successful with P and As, elements with much larger ionic radii than that of O. Although ZnO substrates are now available, most of the epitaxial p-type layers so far have been grown on sapphire, or other poorly-matched materials. The lowest p-type resistivity obtained up to now is about 0.5 Ω-cm, which should be sufficient for LED fabrication. In spite of the present availability of p-type ZnO, very few homojunction LEDs have been reported so far, to our knowledge; however, several good heterojunction LEDs have been demonstrated, fabricated with p-type layers composed of other materials. One such structure, with fairly strong 389-nm emission at 300 K, involves n-type ZnO and p-type AlGaN, grown on an SiC substrate. Also, an N + -ion implanted ZnO layer, deposited by chemical vapor deposition on Al 2 O 3 , exhibits 388-nm emission at 300 K and could be economical to produce.

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

[2]  A. Lusson,et al.  Electrical activity of nitrogen acceptors in ZnO films grown by metalorganic vapor phase epitaxy , 2003 .

[3]  Kakuya Iwata,et al.  Interactions between gallium and nitrogen dopants in ZnO films grown by radical-source molecular-beam epitaxy , 2001 .

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

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

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

[7]  I. Suemune,et al.  Nitrogen-Doped p-Type ZnO Layers Prepared with H2O Vapor-Assisted Metalorganic Molecular-Beam Epitaxy , 2002 .

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

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

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

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

[12]  T. Butkhuzi,et al.  The regulation of defect concentrations by means of separation layer in wide-band II-VI compounds , 2001 .

[13]  D. Look,et al.  The Path To ZnO Devices: Donor and Acceptor Dynamics , 2003 .

[14]  I. Jeong,et al.  Spectral responsivity and quantum efficiency of n-ZnO/p-Si photodiode fully isolated by ion-beam treatment , 2003 .

[15]  Gang Xiong,et al.  Control of p- and n-type conductivity in sputter deposition of undoped ZnO , 2002 .

[16]  Matthew Young,et al.  Chemical vapor deposition-formed p-type ZnO thin films , 2003 .

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

[18]  A. Zunger,et al.  Cluster-doping approach for wide-gap semiconductors: the case of p-type ZnO. , 2003, Physical review letters.

[19]  S. Myers,et al.  Quantitative comparisons of dissolved hydrogen density and the electrical and optical properties of ZnO , 2003 .

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

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

[22]  Y. Ryu,et al.  Fabrication of homostructural ZnO p–n junctions and ohmic contacts to arsenic-doped p-type ZnO , 2003 .

[23]  David C. Look,et al.  Fabrication and characterization of n-ZnO/p-AlGaN heterojunction light-emitting diodes on 6H-SiC substrates , 2003 .

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

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

[26]  M. Joseph,et al.  Fabrication of the low-resistive p-type ZnO by codoping method , 2001 .

[27]  J. Y. Lee,et al.  Characterization of films and interfaces in n-ZnO/p-Si photodiodes , 2002 .

[28]  Yanfa Yan,et al.  p-Type ZnO Thin Films Formed by CVD Reaction of Diethylzinc and NO Gas , 2003 .

[29]  R. M. Mehra,et al.  p-type conduction in codoped ZnO thin films , 2003 .

[30]  D. Shen,et al.  Optical properties and electrical characterization of p-type ZnO thin films prepared by thermally oxiding Zn_3N_2 thin films , 2003 .

[31]  Ilgu Yun,et al.  Formation of p-type ZnO film on InP substrate by phosphor doping , 2003 .

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

[33]  J. Y. Lee,et al.  Photoresponse characteristics of n-ZnO/p-Si heterojunction photodiodes , 2002 .

[34]  Z. Ye,et al.  Growth of N-doped p-type ZnO films using ammonia as dopant source gas , 2003 .

[35]  Z. Ye,et al.  p-type ZnO films deposited by DC reactive magnetron sputtering at different ammonia concentrations , 2003 .

[36]  H. Ohta,et al.  Near-UV emitting diodes based on a transparent p-n junction composed of heteroepitaxially grown p-SrCu2O2 and n-Zno , 2002 .

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

[38]  H. Ohta,et al.  Fabrication and characterization of ultraviolet-emitting diodes composed of transparent p-n heterojunction, p-SrCu2O2 and n-ZnO , 2001 .

[39]  Tomoji Kawai,et al.  p-Type conduction in transparent semiconductor ZnO thin films induced by electron cyclotron resonance N2O plasma , 2002 .

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

[41]  D. Look,et al.  Observation of 430 nm Electroluminescence from ZnO/GaN Heterojunction Light-Emitting Diodes , 2003 .

[42]  D. C. Reynolds,et al.  Neutral-Donor-Bound-Exciton Complexes in ZnO Crystals , 1998 .

[43]  Tetsuya Yamamoto,et al.  Codoping for the fabrication of p-type ZnO , 2002 .

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

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

[46]  Hideo Hosono,et al.  Fabrication and characterization of heteroepitaxial p-n junction diode composed of wide-gap oxide semiconductors p-ZnRh2O4/n-ZnO , 2003 .

[47]  M. Strassburg,et al.  Optical Properties of the Nitrogen Acceptor in Epitaxial ZnO , 2002 .

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

[49]  D. Look,et al.  Remote hydrogen plasma processing of ZnO single crystal surfaces , 2003 .

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