| 1. |
- Mock, Alyssa, et al.
(författare)
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Band-to-band transitions, selection rules, effective mass, and excitonic contributions in monoclinic beta-Ga2O3
- 2017
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Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 96:24
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Tidskriftsartikel (refereegranskat)abstract
- We employ an eigenpolarization model including the description of direction dependent excitonic effects for rendering critical point structures within the dielectric function tensor of monoclinic beta-Ga2O3 yielding a comprehensive analysis of generalized ellipsometry data obtained from 0.75-9 eV. The eigenpolarization model permits complete description of the dielectric response. We obtain, for single-electron and excitonic band-to-band transitions, anisotropic critical point model parameters including their polarization vectors within the monoclinic lattice. We compare our experimental analysis with results from density functional theory calculations performed using the Gaussian-attenuation-Perdew-Burke-Ernzerhof hybrid density functional. We present and discuss the order of the fundamental direct band-to-band transitions and their polarization selection rules, the electron and hole effective mass parameters for the three lowest band-to-band transitions, and their excitonic contributions. We find that the effective masses for holes are highly anisotropic and correlate with the selection rules for the fundamental band-to-band transitions. The observed transitions are polarized close to the direction of the lowest hole effective mass for the valence band participating in the transition.
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| 2. |
- Moustakas, Theodore D., et al.
(författare)
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Jacques Isaac Pankove
- 2017
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Ingår i: Physics today. - : American Institute of Physics (AIP). - 0031-9228 .- 1945-0699. ; 70:4, s. 64-64
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Jacques was born in Chernihiv, Ukraine, on 23 November 1922. A year later he and his family immigrated to Constantinople, and the following year they moved to Marseilles, France. After the Nazis occupied the city in 1942, he and his family immigrated to the US and settled in Oakland, California. He attended the University of California, Berkeley, where he received his BS in 1944 and his MS in 1948, both in electrical engineering. Between getting the two degrees, Jacques enlisted in the US Army Signal Corps and served in the Philippines. He earned his PhD from the University of Paris in 1960 for his work on IR emission in germanium.....
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| 3. |
- Nguyen, Son Tien, 1953-, et al.
(författare)
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Defects and impurities in β-Ga2O3
- 2019
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Ingår i: Ultra-Wide Bandgap Semiconductor Materials. - : Elsevier. - 9780128154687 - 9780128172568 ; , s. 331-345
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Paskov, Plamen P., 1959-, et al.
(författare)
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Optical Properties of III-Nitride Semiconductors
- 2017. - 1
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Ingår i: Handbook of GaN Semiconductor Materials and Devices. - Boca Raton : CRC Press. - 9781498747134 - 9781498747141 ; , s. 87-116
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Bokkapitel (refereegranskat)abstract
- The optical properties of the group-III-nitride materials are obviously of direct relevance for optoelectronic applications, but experiments measuring optical properties also give information on a range of electronic properties. There is already a wealth of data in the literature on the optical properties of III-nitrides [1–4], and here we will concentrate on some of the most recent additions to the scientific knowledge. The focus, looking at the present situation concerning technical applications of these materials, has been on GaN, InGaN, and AlGaN in recent decades. AlGaN materials are important for ultraviolet (UV) emitters and high electron mobility transistor (HEMT) structures and AlGaN optical properties have accordingly been studied over the entire Al composition range. InGaN materials (with In content <50%) have also been studied extensively, and the light-emitting diode (LED) applications based on InGaN/GaN quantum structures have already been awarded a Nobel Prize in 2014. However, the applications of InN are lagging behind. The development of growth procedures for InN and In-rich InGaN has been difficult, and their optical properties were consequently much less studied in the past.
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| 5. |
- Paskov, Plamen P., 1959-, et al.
(författare)
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Point Defects in group-III nitrides
- 2018. - 1
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Ingår i: Defects in Advanced Electronic Materials and Novel Low Dimensional Structures. - : Woodhead Publishing Limited. - 9780081020531 - 9780081020548 ; , s. 27-61
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Bokkapitel (refereegranskat)abstract
- Point defects in semiconductors play a fundamental role for the material properties. Dopants like impurities forming shallow donors and acceptors provide the means of controlling the electrical conductivity of the material, which is the basis of many applications in devices. Native defects like vacancies and interstitial atoms, and their combination with impurities introduce, mostly unwanted deep levels in the bandgap, and thus may serve as traps or recombination centers for the carriers. Some of these defects are introduced during the growth of the material, others by the processing steps necessary in the device production. In this chapter, we present current knowledge about point defects in the III-nitrides based on recent works, both experimental and theoretical, in the field. Materials discussed are AlN, GaN and InN and the ternary alloys between them.
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