Wafer bending and cracking in the hvpe growth were partly settled by pulsed flow modulation method. Zno nanorods were well aligned and perpendicular to the gan substrate, and some of the samples were almost fully chemically etched into nanotubes. Based in the department of electronic and electrical engineering at the university of sheffield we are keen to share research insights, build successful partnerships and strengthen links with industry and academia. Zno films were deposited on indium tin oxide ito, which formed the transparent conductive layer tcl of a gan based lightemitting diode led, by ultrasonic spraying pyrolysis to increase the light output power. The pace of advances in these areas has been remarkable and the wide band gap community relies on books like the one we are. In order to solve the problems of gan heteroepitaxy on sapphire substrate, some techniques were explored. The zno then served as a sacrificial release layer, allowing chemical liftoff of the gan from the cal 2 o 3 substrate via selective wet etching of the zno. Ganbased lightemitting diode with zno nanotexture layer. Therefore, a large number of semiconductor optoelectronic devices adopt. Zno are among the most favored materials for spintronic applications. Gan and znobased materials and devices springer series in. The fabrication of white lightemitting diodes using the n. An understanding of the epitaxial growth mode and strain generation and relaxation processes in these systems is imperative to constructively exploit strain inhomogenities.
Arehart,1 and siddharth rajan1,3 1department of electrical and computer engineering, the ohio state university, columbus, ohio 43210, usa 2department of chemistry and biochemistry, the ohio state university, columbus, ohio 43210, usa. Based in the department of electronic and electrical engineering at the university of sheffield we are keen to share research insights, build successful partnerships and. Proposed devices are believed to pave the way for the ganbased stable flexibletransparent electronics after further materials and process optimization. This first systematic, authoritative and thorough treatment in one comprehensive volume presents the fundamentals and technologies of the topic, elucidating all aspects of zno materials and devices. In this paper, we present a nanowire based light emitting diode led consisting of a ptype gan thin film and an ntype zno vertical nanowire array. It has a high thermal conductivity and a high mobility 41, 42. Great efforts are being made on the wide bandgap materials as mandated by next generation device design and fabrications. The possible importance of zincoxidebased optoelectronic devices is. Gan and znobased materials and devices qian sun, jung. Gan and zno devices and materials deemed critical to both the gan and znobased. It is easy to obtain the high quality ntype zno material by doping groupiii.
Recently, the fabrication of ptype zno has made great progress by monodoping group v elements n, p, as, and sb and codoping iiiv elements with various technologies. Zno, gan, atomic layer deposition, microbolometer, thin film transistor. Using the piezoelectric polarization charges created at the metalgan nanobelt nb interface under strain to modulate transport of local charge carriers across the schottky barrier, the piezotronic effect is utilized to convert mechanical stimuli applied on the wurtzitestructured gan nb into electronic controlling signals, based on which the gan nb straingated transistors sgts have been. On the other hand, the synthesis of high quality zno nanorods is quite difficult due to the lack of lattice matched substrate materials. Highperformance ultraviolet lightemitting diodes using n. Highly ordered and vertically aligned zno nanorod arrays on the pgan substrates were achieved. Growth and characterization of zno based semiconductor. One promising way to enhance the ultraviolet luminescence efficiency is by incorporating plasmonic nanostructures.
Piezotronic effect on zno nanowire film based temperature sensor. Fabrication of zinc oxide nanorods based heterojunction devices using simple and. The alingan and zno materials systems have proven to be one of the. Such widebandgap semiconductor materials have shown promising applications in terahertz optoelectronics. The integration of 2d, layered, pdoped semiconductors like mos 2 with wide band gap materials could provide an avenue towards achieving highperformance, bipolar devices that were otherwise unattainable due to the aforementioned obstacles. Jul, 20 in this study, ntype zno ptype gan and ntype zno nioptype gan based white lightemitting diodes are designed using two known morphologies of zno including nanorods and nanotubes. A dissertation submitted in partial fulfillment of the requirements. Therefore, zno has turned into a new hot focus in the field of shortwavelength laser and. In addition, zno and gan are well suited materials because of the low lattice mismatch of about 1. Nanoscale zno features are embedded in an elastomeric matrix function as tunable diffraction gratings, capable of sensing displacements with nanometre accuracy. Zno nanowires have attracted a lot of attention due to their good charge carrier transport properties and high crystalline quality. Dilute magnetic semiconductors based on gan and zno. It is found that the zno nanorodbased leds exhibit a stronger uv emission of 390nm compared with the zno. Pdf zno and gan nanowire based type ii heterostructures.
Novel method for reclaimreuse of bulk gan substrates. The alingan and zno materials systems have proven to be one of the scientifically and technologically important areas of development over the past 15 years, with applications in uvvisible optoelectronics and in highpowerhighfrequency microwave devices. Aqueous epitaxial growth of zno on single crystalline au. The structure, surface morphology, composition, and optical properties of these thin films were investigated by xray diffraction, field emission scanning electron microscopy, infrared absorption. Hybrid green leds based on n znoingangan multiquantumwells pgan c. A schematic view of a bent gan nanowire with the wurtzite structure and a hexagonal cross section. William bill nehrer, applied materials 2d1 low leakage mgcompensated gan schottky diodes on freestanding gan substrate for high energy. Pdf growth of gan on zno for solid state lighting applications. Ultravioletblue lightemitting diodes based on single. Recent advances in zno materials and devices sciencedirect. The research work presented in this dissertation is based on two direct and wide band gap semiconductors. Gan and znobased materials and devices springer series in materials science pearton, stephen on.
Morphology control and electroluminescence of zno nanorodgan. The inhomogenities due to strain have been favorably used to increase efficiency of solid state light devices based on gan and zno. Freestanding gan substrates have been made by hydride vapor phase epitaxy hvpe, laser liftoff llo, and chemical mechanical polishing techniques. Zno along with gan has attracted intense attention in the search for hight c ferromagnetic diluted magnetic semiconductor dms materials, since dietls prediction that gan and zno based dms systems could exhibit ferromagnetism above room temperature upon doping with transition elements such as mn. Sic, gan, zno, ga2o3, and diamond, find many applications in microelectronics such as high electron mobility transistors hemt, field effect transistors, and lightemitting diodes led. Gan material is considered as an excellent choice for efficient and durable device fabrication 4345.
The optical, dielectric or electric properties of bulk crystalline gan, zno, and zns, and nanostructured zno and zns were characterized by terahertz timedomain spectroscopy measurements. The primary role of piezotronic effect over geometrical and piezoresistive effect in the asfabricated devices has been. These results could have important implications on the advancement of metalznobased electronic devices,5 plasmonic devices,6,7 and heterogeneous catalysts. Despite intense research efforts during the last years, the origin of the magnetic order is still under debate. Wp3 is dedicated to the synthesis, either by vacuum based methods cvd, ald, pvd or wetchemistry. This work provides a route for developing high performance optoelectronic devices based on zno nanorods. Transferrable gan layers grown on znocoated graphene layers for optoelectronic devices kunook chung,1 chulho lee,1,2 gyuchul yi1 to whom correspondence should be addressed.
A high performance selfpowered ultraviolet photodetector based on. Ultraviolet electroluminescence from ordered zno nanorod. Novel process for direct bonding of gan onto glass. The zno nanotexture was formed by treating the asdeposited zno films with hydrogen. Semiconductor materials and structures for power electronics. Hybrid green leds based on znoingangan multiquantum. Fabrication and characterization of zno and gan devices for. Gan material is a chemically and mechanically stable. Effective ultraviolet lightemitting diodes leds were fabricated by clamping the nzno films on the top of phbnpgansapphire substrates.
Gan based devices have promising prospects in military, satellite and commercial applications. In oxidebased materials and devices v 898719 proceedings of spie the international society for optical engineering. Cationmutation design of quaternary nitride semiconductors. On the irst fpart of the dissertation, the synthesis of zno nanorod array via the low temperature solution growth method on flexible. Structural property of znogan thin films figure 1a,b,c shows the xrd spectra of znosi, gansi, and znogansi films. Again, zno owns a huge potentially commercial value due to its cheaper price, abundant resources in nature, environmentally friendly, simple fabrication processes and so on.
Pdf challenges and opportunities in gan and zno devices and. Fabrication and characterization of zno and gan devices. Gan and znobased materials and devices pdf free download. Springer series inmaterials science156 springer series inmaterials science editors. Gan for device applications owing to its relatively low. However, a large energy mismatch between the plasmons and the light emitters greatly li. Gan nanobeltbased straingated piezotronic logic devices. Razeghi a acenter for quantum devices, department of electrical engineering and computer science, northwestern university, evanston, illinois, usa 60208. Znobased devices and applications deals with zno nanostructures nanowires, nanobelts, etc. These devices and the microtectonic oxide thin film approach show promise in enabling functional, transparent, and wearable electronics. Transferrable gan layers grown on znocoated graphene layers. Ultraviolet lightemitting materials and devices with highefficiency are required for many applications. We develop cuttingedge technologies and perform advanced research on iiinitride materials and devices. The semiconductor zno has gained substantial interest in the research community in part because of its large exciton binding energy 60 mev which could lead to lasing action based on exciton recombination even above room temperature.
Gan and znobased materials and devices qian sun, jung han auth. In this work, we demonstrated the first study of piezotronic effect as a potential means for measuring temperature by utilizing zno nanowire nw film. Review of ganzno hybrid structures based materials and. Figure 1a shows that the reflection peaks of 100, 002, and 101 correspond to hexagonal zno with a wurtzite structure, but a preferred orientation along the. The alingan and zno materials systems have proven to be one of the scientifically and technologically important areas of development over. Transferrable gan layers grown on znocoated graphene. Epitaxial growth of zno nanowall networks on gansapphire. Gan and znobased materials and devices springer series in materials science. Epitaxial growth of zno nanowall networks on gansapphire substrates sangwoo kima and hyunkyu park school of advanced materials and system engineering, kumoh national institute of technology, gumi, gyeongbuk 730701, korea minsu yi department of materials science and engineering, sangju national university, sangju, gyeongbuk 742711, korea. Gan was grown on znobuffered csapphire cal 2 o 3 substrates by metal organic vapor phase epitaxy. Proposed devices are believed to pave the way for the gan based stable flexibletransparent electronics after further materials and process optimization. The commercial success of ganbased optoelectronic and electronic devices trig.
Growth of gan on zno for solid state lighting applications. Improvement of electroluminescent performance of nznoalnp. Fabrication of zinc oxide nanorods based heterojunction devices. A number of years ago, gan emerged as the leading material from which. Review of ganzno hybrid structures based materials and devices. Zno thin film templates for ganbased devices article pdf available in proceedings of spie the international society for optical engineering 5732 march 2005 with 98 reads how we measure reads. Gan and znobased materials and devices springerlink. Improvement of electroluminescent performance of n. Recently, an nznocspbbr3pgan selfpowered uv photodetector using a. On the irst fpart of the dissertation, the synthesis of zno nanorod array via the low temperature solution growth method on flexible in 2o 3pet and rigid itoglass substrates were discussed. Mcculloch,2 sriram krishnamoorthy,1 yiying wu,2 aaron r. Thin film epitaxy, defects and interfaces in gansapphire. Zno and gan nanowire based type ii heterostructures. Gan and znobased materials and devices stephen pearton.
Gan and znobased materials and devices springer series. Since mocvd is the dominant growth technology for ganbased materials and devices, there is a need to more. Chapter one introduction background of the research. Novel method for reclaimreuse of bulk gan substrates using sacrificial zno release layers. Nano express open access fabrication and properties of. Morphology control and electroluminescence of zno nanorod. Fabrication and properties of znogan heterostructure.
Following an introduction, the authors look at the general properties of zno, as well as its growth, optical processes, doping and znobased dilute magnetic semiconductors. Element analysis shows that the doping concentration of sb is. Novel znobased ternary oxides for optoelectronic applications. Periodic boundary conditions are used along the axis of the nanowire. The film was synthesized by the wet chemical deposition method and transferred to a flexible substrate using photoresist.
Therefore, zno has turned into a new hot focus in the field of shortwavelength laser and optoelectronic devices in succession to gan in the past decade. Vertically wellaligned zno nanowires on cal2o3 and gan. Emergence of sic and gan materials for optoelectronic applications provides unique opportunity for advancement in power electronics gallium nitride. Zno films were deposited on indium tin oxide ito, which formed the transparent conductive layer tcl of a ganbased lightemitting diode led, by ultrasonic spraying pyrolysis to increase the light output power.
Even though research focusing on zno goes back many decades, the renewed interest is fueled by availability of highquality substrates and reports of ptype. On the photonics side, the algainn materials system, consisting of algan gan, inaln gan, and ingan gan heterostructures and the gan, aln, and inn binaries, is widely used in bluevioletwhiteuv light emitting diodes for stoplights and full color displays, blue and green lasers for use in highdensity cdrom storage and highresolution printers. Pdf this special issue addresses to a large extent the challenges and. Morphology control and electroluminescence of zno nanorodgan heterojunctions prepared using aqueous solution samdong lee, yoonseok kim, minsu yi, jaeyoung choi, and sangwoo kim, school of advanced materials and system engineering, kumoh national institute of technology. The wellaligned zno nanorods were synthesized on gan coated alum. Structure, microstructure and physical properties of zno. Thin film epitaxy, defects and interfaces in gansapphire and.
Besides these established applications, zno and its ternary alloys are now also being considered as potential materials for. Novel method for reclaimreuse of bulk gan substrates using. Wurtzite polar crystal structure, algangan heterostructures, good electronic transport properties. Engineering future light emitting diodes and photovoltaics. Pdf zno is an attractive material for applications in electronics, photonics. Over 10 million scientific documents at your fingertips. Following an introduction, the authors look at the general properties of zno, as well as its growth, optical processes, doping and zno based dilute magnetic semiconductors. In this paper, we present a nanowirebased light emitting diode led consisting of a ptype gan thin film and an ntype zno vertical nanowire array.