Influence of Electron Trapping on Minority Carrier Transport Properties of Wide Band Gap Semiconductors

Influence of Electron Trapping on Minority Carrier Transport Properties of Wide Band Gap Semiconductors
Author: Olena Lopatiuk Tirpak
Publisher:
Total Pages: 110
Release: 2007
Genre:
ISBN:

Minority carrier transport properties and the effects of electron irradiation/injection were studied in GaN and ZnO containing dopants known to form acceptor states deep within the materials’ bandgap. Minority carrier diffusion length and lifetime changes were investigated using Electron Beam Induced Current (EBIC) method, cathodoluminescence spectroscopy, spectral photoresponse and persistent photoconductivity measurements. It is shown that electron irradiation by the beam of a scanning electron microscope results in a significant increase of minority carrier diffusion length. These findings are supported by the cathodoluminescence measurements that demonstrate the decay of near-band-edge intensity as a consequence of increasing carrier lifetime under continuous irradiation by the electron beam. Temperature-dependent measurements were used to determine the activation energies for the electron irradiation-induced effects. The latter energies were found to be consistent with the involvement of deep acceptor states. Based on these findings, the effects of electron irradiation are explained via the mechanism involving carrier trapping on these levels. Solid-state electron injection was also shown to result in a similar increase of minority carrier lifetime and diffusion length. Solid-state injection was carried out by applying the forward bias to a ZnO homojunction and resulted in a significant improvement of the peak photoresponse of the junction. This improvement was unambiguously correlated with the increase of the minority carrier diffusion length due to electron injection.

Wide-Bandgap Electronic Devices: Volume 622

Wide-Bandgap Electronic Devices: Volume 622
Author: R. J. Shul
Publisher:
Total Pages: 578
Release: 2001-04-09
Genre: Technology & Engineering
ISBN:

Interest in wide-bandgap semiconductors for high-power/high-temperature electronics remains prominent. For such applications, SiC is by far the most mature semiconductor material. GaN and diamond, however, have also become prime candidates. While diamond has several advantages over the other two materials, producing large single crystals, as well as the inability to achieve n-type doping, have limited device fabrication. For GaN, recent advances in crystal growth and processing capabilities, as well as excellent transport properties, have yielded a great deal of device development, yet thermal conduction remains an issue. SiC has excellent thermal conductivity, high-breakdown voltages, and well-developed substrates and processing techniques. This book deals with a wide range of technical activity in the area of wide-bandgap high-power/high-temperature electronic devices and covers topics including the fabrication and performance of GaN-based and SiC-based devices, as well as issues related to growth, characterization, and processing of wide-bandgap materials. Several summaries of the current status of the field are provided.

Ultrawide Bandgap Semiconductors

Ultrawide Bandgap Semiconductors
Author:
Publisher: Academic Press
Total Pages: 480
Release: 2021-07-26
Genre: Science
ISBN: 0128228717

Ultrawide Bandgap Semiconductors, Volume 107 in the Semiconductors and Semimetals series, highlights the latest breakthrough in fundamental science and technology development of ultrawide bandgap (UWBG) semiconductor materials and devices based on gallium oxide, aluminium nitride, boron nitride, and diamond. It includes important topics on the materials growth, characterization, and device applications of UWBG materials, where electronic, photonic, thermal and quantum properties are all thoroughly explored. Contains the latest breakthrough in fundamental science and technology development of ultrawide bandgap (UWBG) semiconductor materials and devices Provides a comprehensive presentation that covers the fundamentals of materials growth and characterization, as well as design and performance characterization of state-of-the-art UWBG materials, structures, and devices Presents an in-depth discussion on electronic, photonic, thermal, and quantum technologies based on UWBG materials

Radiation Effects on Wide Band Gap Semiconductor Transport Properties

Radiation Effects on Wide Band Gap Semiconductor Transport Properties
Author: Casey Minna Schwarz
Publisher:
Total Pages: 109
Release: 2012
Genre:
ISBN:

In this research, the transport properties of ZnO were studied through the use of electron and neutron beam irradiation. Acceptor states are known to form deep in the bandgap of doped ZnO material. By subjecting doped ZnO materials to electron and neutron beams we are able to probe, identify and modify transport characteristics relating to these deep accepter states. The impact of irradiation and temperature on minority carrier diffusion length and lifetime were monitored through the use of the Electron Beam Induced Current (EBIC) method and Cathodoluminescence (CL) spectroscopy. The minority carrier diffusion length, L, was shown to increase as it was subjected to increasing temperature as well as continuous electron irradiation. The near-band-edge (NBE) intensity in CL measurements was found to decay as a function of temperature and electron irradiation due to an increase in carrier lifetime. Electron injection through application of a forward bias also resulted in a similar increase of minority carrier diffusion length. Thermal and electron irradiation dependences were used to determine activation energies for the irradiation induced effects. This helps to further our understanding of the electron injection mechanism as well as to identify possible defects responsible for the observed effects. Thermal activation energies likely represent carrier delocalization energy and are related to the increase of diffusion length due to the reduction in recombination efficiency. The effect of electron irradiation on the minority carrier diffusion length and lifetime can be attributed to the trapping of non-equilibrium electrons on neutral acceptor levels. The effect of neutron irradiation on CL intensity can be attributed to an increase in shallow donor concentration. Thermal activation energies resulting from an increase in L or decay of CL intensity monitored through EBIC and CL measurements for p-type Sb doped ZnO were found to be the range of E[subscript a] = 112 to 145 meV. P-type Sb doped ZnO nanowires under the influence of temperature and electron injection either through continuous beam impacting or through forward bias, displayed an increase in L and corresponding decay of CL intensity when observed by EBIC or CL measurements. These measurements led to activation energies for the effect ranging from E[subscript a] = 217 to 233 meV. These values indicate the possible involvement of a Sb[subscript Zn-]2V[subscript Zn] acceptor complex. For N-type unintentionally doped ZnO, CL measurements under the influence of temperature and electron irradiation by continuous beam impacting led to a decrease in CL intensity which resulted in an electron irradiation activation energy of approximately E[subscript a] = 259 meV. This value came close to the defect energy level of the zinc interstitial. CL measurements of neutron irradiated ZnO nanostructures revealed that intensity is redistributed in favor of the NBE transition indicating an increase of shallow donor concentration. With annealing contributing to the improvement of crystallinity, a decrease can be seen in the CL intensity due to the increase in majority carrier lifetime. Low energy emission seen from CL spectra can be due to oxygen vacancies and as an indicator of radiation defects.

Ultra-wide Bandgap Semiconductor Materials

Ultra-wide Bandgap Semiconductor Materials
Author: Meiyong Liao
Publisher: Elsevier
Total Pages: 503
Release: 2019-06-18
Genre: Technology & Engineering
ISBN: 0128172568

Ultra-wide Bandgap Semiconductors (UWBG) covers the most recent progress in UWBG materials, including sections on high-Al-content AlGaN, diamond, B-Ga2O3, and boron nitrides. The coverage of these materials is comprehensive, addressing materials growth, physics properties, doping, device design, fabrication and performance. The most relevant and important applications are covered, including power electronics, RF electronics and DUV optoelectronics. There is also a chapter on novel structures based on UWBG, such as the heterojunctions, the low-dimensional structures, and their devices. This book is ideal for materials scientists and engineers in academia and R&D searching for materials superior to silicon carbide and gallium nitride. Provides a one-stop resource on the most promising ultra-wide bandgap semiconducting materials, including high-Al-content AlGaN, diamond, β-Ga2O3, boron nitrides, and low-dimensional materials Presents comprehensive coverage, from materials growth and properties, to device design, fabrication and performance Features the most relevant applications, including power electronics, RF electronics and DUV optoelectronics

Nitride Wide Bandgap Semiconductor Material and Electronic Devices

Nitride Wide Bandgap Semiconductor Material and Electronic Devices
Author: Yue Hao
Publisher: CRC Press
Total Pages: 389
Release: 2016-11-03
Genre: Computers
ISBN: 149874513X

This book systematically introduces physical characteristics and implementations of III-nitride wide bandgap semiconductor materials and electronic devices, with an emphasis on high-electron-mobility transistors (HEMTs). The properties of nitride semiconductors make the material very suitable for electronic devices used in microwave power amplification, high-voltage switches, and high-speed digital integrated circuits.

Wide Bandgap Semiconductor Electronics And Devices

Wide Bandgap Semiconductor Electronics And Devices
Author: Uttam Singisetti
Publisher: World Scientific
Total Pages: 258
Release: 2019-12-10
Genre: Technology & Engineering
ISBN: 9811216495

'This book is more suited for researchers already familiar with WBS who are interested in developing new WBG materials and devices since it provides the latest developments in new materials and processes and trends for WBS and UWBS technology.'IEEE Electrical Insulation MagazineWith the dawn of Gallium Oxide (Ga2O₃) and Aluminum Gallium Nitride (AlGaN) electronics and the commercialization of Gallium Nitride (GaN) and Silicon Carbide (SiC) based devices, the field of wide bandgap materials and electronics has never been more vibrant and exciting than it is now. Wide bandgap semiconductors have had a strong presence in the research and development arena for many years. Recently, the increasing demand for high efficiency power electronics and high speed communication electronics, together with the maturity of the synthesis and fabrication of wide bandgap semicon-ductors, has catapulted wide bandgap electronics and optoelectronics into the mainstream.Wide bandgap semiconductors exhibit excellent material properties, which can potentially enable power device operation at higher efficiency, higher temperatures, voltages, and higher switching speeds than current Si technology. This edited volume will serve as a useful reference for researchers in this field — newcomers and experienced alike.This book discusses a broad range of topics including fundamental transport studies, growth of high-quality films, advanced materials characterization, device modeling, high frequency, high voltage electronic devices and optical devices written by the experts in their respective fields. They also span the whole spectrum of wide bandgap materials including AlGaN, Ga2O₃and diamond.

Wide Bandgap Semiconductor Power Devices

Wide Bandgap Semiconductor Power Devices
Author: B. Jayant Baliga
Publisher: Woodhead Publishing
Total Pages: 420
Release: 2018-10-17
Genre: Technology & Engineering
ISBN: 0081023073

Wide Bandgap Semiconductor Power Devices: Materials, Physics, Design and Applications provides readers with a single resource on why these devices are superior to existing silicon devices. The book lays the groundwork for an understanding of an array of applications and anticipated benefits in energy savings. Authored by the Founder of the Power Semiconductor Research Center at North Carolina State University (and creator of the IGBT device), Dr. B. Jayant Baliga is one of the highest regarded experts in the field. He thus leads this team who comprehensively review the materials, device physics, design considerations and relevant applications discussed. Comprehensively covers power electronic devices, including materials (both gallium nitride and silicon carbide), physics, design considerations, and the most promising applications Addresses the key challenges towards the realization of wide bandgap power electronic devices, including materials defects, performance and reliability Provides the benefits of wide bandgap semiconductors, including opportunities for cost reduction and social impact