ZnO-on-GaN heterojunction light-emitting diode grown by vapor cooling condensation technique

The growth of ZnO-on-GaN heterostructures was implemented using the vapor cooling condensation system. The technique thus developed was employed to fabricate both the p-GaN∕n-ZnO:In (p-n) and p-GaN∕i-ZnO∕n-ZnO:In (p-i-n) heterojunction light-emitting diodes (LEDs). A rectifying diodelike behavior was clearly observed from both the p-n and p-i-n heterojunction LEDs, with the forward turn-on voltage of 3V and the reverse breakdown voltage of −15V determined for the p-n heterojunction LEDs, compared to 7 and −23V, respectively, for the p-i-n heterojunction LEDs. Based on the results of photoluminescence and electroluminescence studies conducted on these LED structures, the ZnO layer responsible for the peak emission wavelength of 385nm were also verified experimentally.

[1]  Mitsuaki Yano,et al.  Characteristics of a Zn0.7Mg0.3O∕ZnO heterostructure field-effect transistor grown on sapphire substrate by molecular-beam epitaxy , 2005 .

[2]  H. Ohta,et al.  Thin-Film Transistor Fabricated in Single-Crystalline Transparent Oxide Semiconductor , 2003, Science.

[3]  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 .

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

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

[6]  David C. Look,et al.  The Future Of ZnO Light Emitters , 2004 .

[7]  Seong-Ju Park,et al.  p-ZnO/n-GaN heterostructure ZnO light-emitting diodes , 2005 .

[8]  M. Asif Khan,et al.  Violet‐blue GaN homojunction light emitting diodes with rapid thermal annealed p‐type layers , 1995 .

[9]  H. Makino,et al.  Capacitance-voltage characteristics of ZnO/GaN heterostructures , 2005 .

[10]  Guanzhong Wang,et al.  Optical properties of ZnO/GaN heterostructure and its near-ultraviolet light-emitting diode , 2003 .

[11]  Takafumi Yao,et al.  Band alignment at a ZnO/GaN (0001) heterointerface , 2001 .

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

[13]  H. Makino,et al.  Electron-trap centers in ZnO layers grown by molecular-beam epitaxy , 2005 .

[14]  David P. Norton,et al.  Wide band gap ferromagnetic semiconductors and oxides , 2003 .