Sökning: "III-Nitrides"

Visar resultat 1 - 5 av 24 avhandlingar innehållade ordet III-Nitrides.

1. 1. GaN, AlGaN, GaNAs and Related Heterostructures Grown by Molecular Beam Epitaxy

   Författare :Hyonju Kim; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; surface segregation; GaNAs; plasma-assisted MBE; stacking fault; AlGaN GaN; heterointerface; unintentional impurities; III-nitrides;

   Sammanfattning : This work deals with growth and characterization of III-nitrides and related heterostructures as well as GaNAs alloys grown by plasma assisted molecular beam epitaxy (MBE). The III-nitrides belong to the wide bandgap semiconductors due to their large energy bandgap spanning from 1.9 to 6.2 eV. LÄS MER

3. 2. Optical studies of AlN and GaO based nanostructures using Mueller matrix spectroscopic ellipsometry

   Författare :Samiran Bairagi; Kenneth Järrendahl; Ching-Lien Hsiao; Bruno Gallas; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GLAD; MMSE; PVD; III-nitrides; Oxides; Anisotropy; Bandgap;

   Sammanfattning : This thesis explores the diverse optical properties manifested when light interacts with various materials, with an emphasis on circular polarization- and bandgaprelated phenomena. The studies in this work are centered around Mueller matrix spectroscopic ellipsometry, with the objective of synthesizing and characterizing nanostructured and high-quality thin films to expand our understanding of the optical properties arising from their underlying structure and electronic transitions, respectively. LÄS MER

4. 3. Hot-wall MOCVD for advanced GaN HEMT structures and improved p-type doping

   Författare :Alexis Papamichail; Vanya Darakchieva; Anelia Kakanakova-Gueorguieva; Jr-Tai Chen; Zlatko Sitar; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hot-wall MOCVD; III-nitrides; p-type GaN; HEMTs; Linearity; High-Al barrier;

   Sammanfattning : The transition to energy efficient smart grid and wireless communication with improved capacity require the development and optimization of next generation semiconductor technologies and electronic device components. Indium nitride (InN), gallium nitride (GaN) and aluminum nitride (AlN) compounds and their alloys are direct bandgap semiconductors with bandgap energies ranging from 0. LÄS MER

5. 4. Towards Novel AlGaN-Based Light Emitters

   Författare :Martin Stattin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AlGaN; light emitting diode; deep ultraviolet; III-Nitrides; near infrared; quantum cascade laser;

   Sammanfattning : The unique properties of the AlGaN semiconductors make them a suitable choice for optoelectronic devices at both short and long wavelengths, based on interband and intersubband transitions, respectively. What sets AlGaN apart from other wide-bandgap semiconductors is the possibility to obtain both p- and n-type conductivity as well as the direct bandgap. LÄS MER

7. 5. Thermal conductivity of wide and ultra-wide bandgap semiconductors

   Författare :Dat Tran; Plamen Paskov; Vanya Darakchieva; Martin Kuball; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; III-nitrides; β-Ga2O3; Thermal conductivity; Thermal transport;

   Sammanfattning : This PhD thesis presents experimental and theoretical studies of the thermal conductivity of wide and ultra-wide bandgap semiconductors including GaN, AlN, β-Ga2O3 binary compounds, and AlxGa1−xN, ScxAl1−xN, YxAl1−xN ternary alloys. Thermal conductivity measurements are conducted using the transient thermoreflectance (TTR) technique and the results are interpreted using analytical models based on the solution of the Boltzmann transport equation (BTE) within the relaxation time approximation (RTA). LÄS MER