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The work contained in this dissertation is focused on the optical properties of direct band gap semiconductors which crystallize in a wurtzite structure: more specifically, the III-nitrides and ZnO. By using cathodoluminescence spectroscopy, many of their properties have been investigated, including band gaps, defect energy levels, carrier lifetimes, strain states, exciton binding energies, and effects of electron irradiation on luminescence. Part of this work is focused on p-type Mg-doped GaN and InGaN. These materials are extremely important for the fabrication of visible light emitting diodes and diode lasers and their complex nature is currently not entirely understood. The luminescence of Mg-doped GaN films has been correlated with electrical and structural measurements in order to understand the behavior of hydrogen in the material. Deeply-bound excitons emitting near 3.37 and 3.42 eV are observed in films with a significant hydrogen concentration during cathodoluminescence at liquid helium temperatures. These radiative transitions are unstable during electron irradiation. Our observations suggest a hydrogen-related nature, as opposed to a previous assignment of stacking fault luminescence. The intensity of the 3.37 eV transition can be correlated with the electrical activation of the Mg acceptors. Next, the acceptor energy level of Mg in InGaN is shown to decrease significantly with an increase in the indium composition. This also corresponds to a decrease in the resistivity of these films. In addition, the hole concentration in multiple quantum well light emitting diode structures is much more uniform in the active region when Mg-doped InGaN (instead of Mg-doped GaN) is used. These results will help improve the efficiency of light emitting diodes, especially in the green/yellow color range. Also, the improved hole transport may prove to be important for the development of photovoltaic devices. Cathodoluminescence studies have also been performed on nanoindented ZnO crystals. Bulk, single crystal ZnO was indented using a sub-micron spherical diamond tip on various surface orientations. The resistance to deformation (the "hardness") of each surface orientation was measured, with the c-plane being the most resistive. This is due to the orientation of the easy glide planes, the c-planes, being positioned perpendicularly to the applied load. The a-plane oriented crystal is the least resistive to deformation. Cathodoluminescence imaging allows for the correlation of the luminescence with the regions located near the indentation. Sub-nanometer shifts in the band edge emission have been assigned to residual strain the crystals. The a- and m-plane oriented crystals show two-fold symmetry with regions of compressive and tensile strain located parallel and perpendicular to the ±c-directions, respectively. The c-plane oriented crystal shows six-fold symmetry with regions of tensile strain extending along the six equivalent a-directions.
ContributorsJuday, Reid (Author) / Ponce, Fernando A. (Thesis advisor) / Drucker, Jeff (Committee member) / Mccartney, Martha R (Committee member) / Menéndez, Jose (Committee member) / Shumway, John (Committee member) / Arizona State University (Publisher)
Created2013
Description
Nitride semiconductors have wide applications in electronics and optoelectronics technologies. Understanding the nature of the optical recombination process and its effects on luminescence efficiency is important for the development of novel devices. This dissertation deals with the optical properties of nitride semiconductors, including GaN epitaxial layers and more complex heterostructures. The emission characteristics are examined by cathodoluminescence spectroscopy and imaging, and are correlated with the structural and electrical properties studied by transmission electron microscopy and electron holography. Four major areas are covered in this dissertation, which are described next. The effect of strain on the emission characteristics in wurtzite GaN has been studied. The values of the residual strain in GaN epilayers with different dislocation densities are determined by x-ray diffraction, and the relationship between exciton emission energy and the in-plane residual strain is demonstrated. It shows that the emission energy increases withthe magnitude of the in-plane compressive strain. The temperature dependence of the emission characteristics in cubic GaN has been studied. It is observed that the exciton emission and donor-acceptor pair recombination behave differently with temperature. The donor-bound exciton binding energy has been measured to be 13 meV from the temperature dependence of the emission spectrum. It is also found that the ionization energies for both acceptors and donors are smaller in cubic compared with hexagonal structures, which should contribute to higher doping efficiencies. A comprehensive study on the structural and optical properties is presented for InGaN/GaN quantum wells emitting in the blue, green, and yellow regions of the electromagnetic spectrum. Transmission electron microscopy images indicate the presence of indium inhomogeneties which should be responsible for carrier localization. The temperature dependence of emission luminescence shows that the carrier localization effects become more significant with increasing emission wavelength. On the other hand, the effect of non-radiative recombination on luminescence efficiency also varies with the emission wavelength. The fast increase of the non-radiative recombination rate with temperature in the green emitting QWs contributes to the lower efficiency compared with the blue emitting QWs. The possible saturation of non-radiative recombination above 100 K may explain the unexpected high emission efficiency for the yellow emitting QWs Finally, the effects of InGaN underlayers on the electronic and optical properties of InGaN/GaN quantum wells emitting in visible spectral regions have been studied. A significant improvement of the emission efficiency is observed, which is associated with a blue shift in the emission energy, a reduced recombination lifetime, an increased spatial homogeneity in the luminescence, and a weaker internal field across the quantum wells. These are explained by a partial strain relaxation introduced by the InGaN underlayer, which is measured by reciprocal space mapping of the x-ray diffraction intensity.
ContributorsLi, Di (Author) / Ponce, Fernando (Thesis advisor) / Culbertson, Robert (Committee member) / Yu, Hongbin (Committee member) / Shumway, John (Committee member) / Menéndez, Jose (Committee member) / Arizona State University (Publisher)
Created2012
Description
In order to cope with the decreasing availability of symphony jobs and collegiate faculty positions, many musicians are starting to pursue less traditional career paths. Also, to combat declining audiences, musicians are exploring ways to cultivate new and enthusiastic listeners through relevant and engaging performances. Due to these challenges, many community-based chamber music ensembles have been formed throughout the United States. These groups not only focus on performing classical music, but serve the needs of their communities as well. The problem, however, is that many musicians have not learned the business skills necessary to create these career opportunities. In this document I discuss the steps ensembles must take to develop sustainable careers. I first analyze how groups build a strong foundation through getting to know their communities and creating core values. I then discuss branding and marketing so ensembles can develop a public image and learn how to publicize themselves. This is followed by an investigation of how ensembles make and organize their money. I then examine the ways groups ensure long-lasting relationships with their communities and within the ensemble. I end by presenting three case studies of professional ensembles to show how groups create and maintain successful careers. Ensembles must develop entrepreneurship skills in addition to cultivating their artistry. These business concepts are crucial to the longevity of chamber groups. Through interviews of successful ensemble members and my own personal experiences in the Tetra String Quartet, I provide a guide for musicians to use when creating a community-based ensemble.
ContributorsDalbey, Jenna (Author) / Landschoot, Thomas (Thesis advisor) / McLin, Katherine (Committee member) / Ryan, Russell (Committee member) / Solis, Theodore (Committee member) / Spring, Robert (Committee member) / Arizona State University (Publisher)
Created2013
Description
This project is a practical annotated bibliography of original works for oboe trio with the specific instrumentation of two oboes and English horn. Presenting descriptions of 116 readily available oboe trios, this project is intended to promote awareness, accessibility, and performance of compositions within this genre.
The annotated bibliography focuses exclusively on original, published works for two oboes and English horn. Unpublished works, arrangements, works that are out of print and not available through interlibrary loan, or works that feature slightly altered instrumentation are not included.
Entries in this annotated bibliography are listed alphabetically by the last name of the composer. Each entry includes the dates of the composer and a brief biography, followed by the title of the work, composition date, commission, and dedication of the piece. Also included are the names of publishers, the length of the entire piece in minutes and seconds, and an incipit of the first one to eight measures for each movement of the work.
In addition to providing a comprehensive and detailed bibliography of oboe trios, this document traces the history of the oboe trio and includes biographical sketches of each composer cited, allowing readers to place the genre of oboe trios and each individual composition into its historical context. Four appendices at the end include a list of trios arranged alphabetically by composer's last name, chronologically by the date of composition, and by country of origin and a list of publications of Ludwig van Beethoven's oboe trios from the 1940s and earlier.
The annotated bibliography focuses exclusively on original, published works for two oboes and English horn. Unpublished works, arrangements, works that are out of print and not available through interlibrary loan, or works that feature slightly altered instrumentation are not included.
Entries in this annotated bibliography are listed alphabetically by the last name of the composer. Each entry includes the dates of the composer and a brief biography, followed by the title of the work, composition date, commission, and dedication of the piece. Also included are the names of publishers, the length of the entire piece in minutes and seconds, and an incipit of the first one to eight measures for each movement of the work.
In addition to providing a comprehensive and detailed bibliography of oboe trios, this document traces the history of the oboe trio and includes biographical sketches of each composer cited, allowing readers to place the genre of oboe trios and each individual composition into its historical context. Four appendices at the end include a list of trios arranged alphabetically by composer's last name, chronologically by the date of composition, and by country of origin and a list of publications of Ludwig van Beethoven's oboe trios from the 1940s and earlier.
ContributorsSassaman, Melissa Ann (Author) / Schuring, Martin (Thesis advisor) / Buck, Elizabeth (Committee member) / Holbrook, Amy (Committee member) / Hill, Gary (Committee member) / Arizona State University (Publisher)
Created2014
Description
The repertoire for guitar and piano duo is small in comparison with other chamber music instrumentation; therefore, it is important to broaden this repertoire. In addition to creating original compositions, arrangements of existing works contribute to this expansion.
This project focuses on an arrangement of Bachianas Brasileiras No. 1 by Brazilian composer Heitor Villa-Lobos (1887-1959), a work originally conceived for cello ensemble with a minimum of eight cellos. In order to contextualize the proposed arrangement, this study contains a brief historical listing of the repertoire for guitar and piano duo and of the guitar works by Villa-Lobos. Also, it includes a description of the Bachianas Brasileiras series and a discussion of the arranging methodology that shows how the original musical ideas of the composer were adapted using techniques that are idiomatic to the guitar and piano. The full arrangement is included in Appendix A.
This project focuses on an arrangement of Bachianas Brasileiras No. 1 by Brazilian composer Heitor Villa-Lobos (1887-1959), a work originally conceived for cello ensemble with a minimum of eight cellos. In order to contextualize the proposed arrangement, this study contains a brief historical listing of the repertoire for guitar and piano duo and of the guitar works by Villa-Lobos. Also, it includes a description of the Bachianas Brasileiras series and a discussion of the arranging methodology that shows how the original musical ideas of the composer were adapted using techniques that are idiomatic to the guitar and piano. The full arrangement is included in Appendix A.
ContributorsFigueiredo Bartoloni, Fabio (Author) / Koonce, Frank (Thesis advisor) / Suzuki, Kotoka (Committee member) / Landschoot, Thomas (Committee member) / Arizona State University (Publisher)
Created2016
Description
Phantom Sun is a ten-minute piece in three sections, and is composed for flute, clarinet in b-flat, violin, cello, and percussion. The three-part structure for this work is a representation of the atmospheric phenomenon after which the composition is named. A phantom sun, also called a parhelion or sundog, is a weather-related phenomenon caused by the horizontal refraction of sunlight in the upper atmosphere. This refraction creates the illusion of three suns above the horizon, and is often accompanied by a bright halo called the circumzenithal arc. The halo is caused by light bending at 22° as it passes through hexagonal ice crystals. Consequently, the numbers six and 22 are important figures, and have been encoded into this piece in various ways.
The first section, marked “With concentrated intensity,” is characterized by the juxtaposition of tonal ambiguity and tonal affirmation, as well as the use of polymetric counterpoint (often 7/8 against 4/4 or 7/8 against 3/4). The middle section, marked “Crystalline,” provides contrast in its use of unmetered sections and independent tempos. The refraction of light is represented in this movement by a 22-note row based on a hexachord (B-flat, F, C, G, A, E) introduced in measure 164 of the first section. The third section, marked “With frenetic energy,” begins without pause on an arresting entrance of the drums playing an additive rhythmic pattern. This pattern (5+7+9+1) amounts to 22 eighth-note pulses and informs much of the motivic and structural considerations for the remainder of the piece.
The first section, marked “With concentrated intensity,” is characterized by the juxtaposition of tonal ambiguity and tonal affirmation, as well as the use of polymetric counterpoint (often 7/8 against 4/4 or 7/8 against 3/4). The middle section, marked “Crystalline,” provides contrast in its use of unmetered sections and independent tempos. The refraction of light is represented in this movement by a 22-note row based on a hexachord (B-flat, F, C, G, A, E) introduced in measure 164 of the first section. The third section, marked “With frenetic energy,” begins without pause on an arresting entrance of the drums playing an additive rhythmic pattern. This pattern (5+7+9+1) amounts to 22 eighth-note pulses and informs much of the motivic and structural considerations for the remainder of the piece.
ContributorsMitton, Stephen LeRoy (Author) / DeMars, James (Thesis advisor) / Norton, Kay (Committee member) / Rogers, Rodney (Committee member) / Arizona State University (Publisher)
Created2017
Description
Arnold Schoenberg’s Pierrot Lunaire, written in 1912 for an ensemble of flute, clarinet, piano, violin, cello, and voice
arrator (with certain instrumental doublings), has, since its premiere, greatly influenced composers writing chamber music. In fact, this particular instrumentation has become known as the “Pierrot Ensemble,” with variations on Schoenberg’s creation used by Igor Stravinsky, Luciano Berio, and many other composers.
There are many resources devoted to music for chamber winds composed during the twentieth century, including those inspired by Schoenberg’s configuration. Additionally, many sources have comprehensively covered known chamber music composed before 1900. However, there is very little research dedicated to chamber wind music composed since 2000.
The purpose of this study is to contribute to the body of research about the music by: 1) creating an annotated bibliography of 21st century wind chamber music.; and 2) thereby catalyzing the discovery of recently composed wind chamber music. Moreover, I hope to address and encourage diversity through my research. To that end, the Composer’s Diversity Database was used as a primary resource for discovering compositions written since 2000 for wind/percussion-based ensembles comprising six to thirteen players.
arrator (with certain instrumental doublings), has, since its premiere, greatly influenced composers writing chamber music. In fact, this particular instrumentation has become known as the “Pierrot Ensemble,” with variations on Schoenberg’s creation used by Igor Stravinsky, Luciano Berio, and many other composers.
There are many resources devoted to music for chamber winds composed during the twentieth century, including those inspired by Schoenberg’s configuration. Additionally, many sources have comprehensively covered known chamber music composed before 1900. However, there is very little research dedicated to chamber wind music composed since 2000.
The purpose of this study is to contribute to the body of research about the music by: 1) creating an annotated bibliography of 21st century wind chamber music.; and 2) thereby catalyzing the discovery of recently composed wind chamber music. Moreover, I hope to address and encourage diversity through my research. To that end, the Composer’s Diversity Database was used as a primary resource for discovering compositions written since 2000 for wind/percussion-based ensembles comprising six to thirteen players.
ContributorsBrown, Jr., Fredrick Marcell (Author) / Hill, Gary W. (Thesis advisor) / Caslor, Jason (Committee member) / Schmelz, Peter (Committee member) / Stover, Christopher (Committee member) / Arizona State University (Publisher)
Created2019
Description
ABSTRACT
The purpose of this study is to analyze Tunes from My Home, a Trio for Violin, Cello, and Piano by Chinese-American composer Chen Yi (b. 1953), as well as to provide a performance guide from a collaborative pianist's perspective. Of Cantonese origin herself, Chen Yi composed several works inspired by Cantonese music, including this trio. Chen Yi composed this trio between 2007 and 2008 and dedicated it to her long time friend pianist Pan Xun, who is also of Cantonese origin. Inspired by this shared Cantonese heritage, Chen Yi incorporated within this work three well-known Cantonese tunes, Cantonese instrumental techniques and sonorities, and elements of the shifan luogu, a wind and percussion ensemble often used in traditional Cantonese music. Coming from the same region as the composer, the author of this paper feels connected with this piece, and as a collaborative pianist, has the opportunity to introduce Cantonese music to a wider audience through the piano trio. Chapter one introduces the motivation for this study. Chapter two provides a brief biography of Chen Yi. Chapter three introduces the history, the scales, and the instruments of Cantonese music as well as other Cantonese influences on this trio, especially the three tunes. Chapter four includes a detailed analysis of each movement in terms of the form and application of the tunes and rhythms of Cantonese music. Chapter five shares the author’s experience of approaching and interpreting this piece in an appropriate style based on her Cantonese roots. The conclusion evaluates the significance of the fusion of Cantonese music with Western compositional techniques in this piece.
The purpose of this study is to analyze Tunes from My Home, a Trio for Violin, Cello, and Piano by Chinese-American composer Chen Yi (b. 1953), as well as to provide a performance guide from a collaborative pianist's perspective. Of Cantonese origin herself, Chen Yi composed several works inspired by Cantonese music, including this trio. Chen Yi composed this trio between 2007 and 2008 and dedicated it to her long time friend pianist Pan Xun, who is also of Cantonese origin. Inspired by this shared Cantonese heritage, Chen Yi incorporated within this work three well-known Cantonese tunes, Cantonese instrumental techniques and sonorities, and elements of the shifan luogu, a wind and percussion ensemble often used in traditional Cantonese music. Coming from the same region as the composer, the author of this paper feels connected with this piece, and as a collaborative pianist, has the opportunity to introduce Cantonese music to a wider audience through the piano trio. Chapter one introduces the motivation for this study. Chapter two provides a brief biography of Chen Yi. Chapter three introduces the history, the scales, and the instruments of Cantonese music as well as other Cantonese influences on this trio, especially the three tunes. Chapter four includes a detailed analysis of each movement in terms of the form and application of the tunes and rhythms of Cantonese music. Chapter five shares the author’s experience of approaching and interpreting this piece in an appropriate style based on her Cantonese roots. The conclusion evaluates the significance of the fusion of Cantonese music with Western compositional techniques in this piece.
ContributorsWu, Xuelai (Author) / Campbell, Andrew (Thesis advisor) / DeMars, James (Committee member) / Landschoot, Thomas (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2017
Description
The work of collaborative pianists can vary widely, requiring a large spectrum of musical and foreign language skills. In addition, many non-musical skills are required of collaborative pianists in order to adapt to various types of work, the roles they assume, and the needs of the people they encounter professionally. Collaborative pianists usually develop good habits for survival on the job, but rarely receive preliminary training in capacities such as facilitation, maintaining objectivity in collaboration, asking good questions, and giving feedback effectively. The emerging field of teaching artistry offers a wealth of information for the development of these non-musical skills in collaborative pianists. The skills necessary for teaching artistry and collaborative piano frequently overlap, which is instructive for collaborative pianists as they prepare for their various musical and leadership roles. This paper explores shared practices between these disciplines, how they can enhance the activities of a collaborative pianist, and also help them develop skills as arts advocates. Advocating techniques for new music and audience engagement are addressed, as well as programming, content development and building teams around projects. The idea of the collaborative pianist becoming a teaching artist is also explored, as the diverse activities and experiences of a collaborative pianist can serve as valuable resources. All of these approaches to non-musical skills focus on building strong processes, leading to creative activities that are process-driven rather than product-driven. This study seeks to enrich activities of collaborative pianists through the application of teaching artist capacities and pave pathways for new, more effective professional collaborations.
ContributorsWitt, Juliana (Author) / Campbell, Andrew (Thesis advisor) / Norton, Kay (Committee member) / Ryan, Russell (Committee member) / Swoboda, Deanna (Committee member) / Arizona State University (Publisher)
Created2020
Description
This dissertation covers my doctoral research on the cathodoluminescence (CL) study of the optical properties of III-niride semiconductors.
The first part of this thesis focuses on the optical properties of Mg-doped gallium nitride (GaN:Mg) epitaxial films. GaN is an emerging material for power electronics, especially for high power and high frequency applications. Compared to traditional Si-based devices, GaN-based devices offer superior breakdown properties, faster switching speed, and reduced system size. Some of the current device designs involve lateral p-n junctions which require selective-area doping. Dopant distribution in the selectively-doped regions is a critical issue that can impact the device performance. While most studies on Mg doping in GaN have been reported for epitaxial grown on flat c-plane substrates, questions arise regarding the Mg doping efficiency and uniformity in selectively-doped regions, where growth on surfaces etched away from the exact c-plane orientation is involved. Characterization of doping concentration distribution in lateral structures using secondary ion mass spectroscopy lacks the required spatial resolution. In this work, visualization of acceptor distribution in GaN:Mg epilayers grown by metalorganic chemical vapor deposition (MOCVD) was achieved at sub-micron scale using CL imaging. This was enabled by establishing a correlation among the luminescence characteristics, acceptor concentration, and electrical conductivity of GaN:Mg epilayers. Non-uniformity in acceptor distribution has been observed in epilayers grown on mesa structures and on miscut substrates. It is shown that non-basal-plane surfaces, such as mesa sidewalls and surface step clusters, promotes lateral growth along the GaN basal planes with a reduced Mg doping efficiency. The influence of surface morphology on the Mg doping efficiency in GaN has been studied.
The second part of this thesis focuses on the optical properties of InGaN for photovoltaic applications. The effects of thermal annealing and low energy electron beam irradiation (LEEBI) on the optical properties of MOCVD-grown In0.14Ga0.86N films were studied. A multi-fold increase in luminescence intensity was observed after 800 °C thermal annealing or LEEBI treatment. The mechanism leading to the luminescence intensity increase has been discussed. This study shows procedures that significantly improve the luminescence efficiency of InGaN, which is important for InGaN-based optoelectronic devices.
The first part of this thesis focuses on the optical properties of Mg-doped gallium nitride (GaN:Mg) epitaxial films. GaN is an emerging material for power electronics, especially for high power and high frequency applications. Compared to traditional Si-based devices, GaN-based devices offer superior breakdown properties, faster switching speed, and reduced system size. Some of the current device designs involve lateral p-n junctions which require selective-area doping. Dopant distribution in the selectively-doped regions is a critical issue that can impact the device performance. While most studies on Mg doping in GaN have been reported for epitaxial grown on flat c-plane substrates, questions arise regarding the Mg doping efficiency and uniformity in selectively-doped regions, where growth on surfaces etched away from the exact c-plane orientation is involved. Characterization of doping concentration distribution in lateral structures using secondary ion mass spectroscopy lacks the required spatial resolution. In this work, visualization of acceptor distribution in GaN:Mg epilayers grown by metalorganic chemical vapor deposition (MOCVD) was achieved at sub-micron scale using CL imaging. This was enabled by establishing a correlation among the luminescence characteristics, acceptor concentration, and electrical conductivity of GaN:Mg epilayers. Non-uniformity in acceptor distribution has been observed in epilayers grown on mesa structures and on miscut substrates. It is shown that non-basal-plane surfaces, such as mesa sidewalls and surface step clusters, promotes lateral growth along the GaN basal planes with a reduced Mg doping efficiency. The influence of surface morphology on the Mg doping efficiency in GaN has been studied.
The second part of this thesis focuses on the optical properties of InGaN for photovoltaic applications. The effects of thermal annealing and low energy electron beam irradiation (LEEBI) on the optical properties of MOCVD-grown In0.14Ga0.86N films were studied. A multi-fold increase in luminescence intensity was observed after 800 °C thermal annealing or LEEBI treatment. The mechanism leading to the luminescence intensity increase has been discussed. This study shows procedures that significantly improve the luminescence efficiency of InGaN, which is important for InGaN-based optoelectronic devices.
ContributorsLiu, Hanxiao (Author) / Ponce, Fernando A. (Thesis advisor) / Zhao, Yuji (Committee member) / Newman, Nathan (Committee member) / Fischer, Alec M (Committee member) / Arizona State University (Publisher)
Created2020