Sökning: "ferroelectric domains"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden ferroelectric domains.

  1. 1. Ferroelectric domain engineering and characterization for photonic applications

    Författare :Simonetta Grilli; Fredrik Laurell; Wolfgang Sohler; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LiNbO; KTiOPO; interferometry; digital holography; electric field poling; electro-optic materials; holographic lithography; ferroelectric domains; nanostructures; microstructures; Optical physics; Optisk fysik;

    Sammanfattning : Lithium niobate (LiNbO3) and KTiOPO4 (KTP) are ferroelectric crystals of considerable interest in different fields of optics and optoelectronics. Due to its large values of the nonlinear optical, electro-optic (EO), piezoelectric and acousto-optical coefficients, LiNbO3 is widely used for laser frequency conversion using the quasiphase matching (QPM) approach where the sign of nonlinearity has been periodically modulated by electric field poling (EFP). LÄS MER

  3. 2. Integration of Ferroelectric HfO2 onto a III-V Nanowire Platform

    Författare :Anton E. O. Persson; Nanoelektronik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ferroelectricity; ferroelectric FET; ferroelectric tunnel junction; tunnel field effect transistors; HZO; III-V; nanowire;

    Sammanfattning : The discovery of ferroelectricity in CMOS-compatible oxides, such as doped hafnium oxide, has opened new possibilities for electronics by reviving the use of ferroelectric implementations on modern technology platforms. This thesis presents the ground-up integration of ferroelectric HfO2 on a thermally sensitive III-V nanowire platform leading to the successful implementation of ferroelectric transistors (FeFETs), tunnel junctions (FTJs), and varactors for mm-wave applications. LÄS MER

  4. 3. Domain engineering in KTiOPO4

    Författare :Carlota Canalias; Fredrik Laurell; Benoît Boulanger; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quasi-phase matching; KTiOPO4; ferroelectric domains; atomic force microscopy; periodic electric field poling; polarization switching; second harmonic generation; Optical physics; Optisk fysik;

    Sammanfattning : Ferroelectric crystals are commonly used in nonlinear optics for frequency conversion of laser radiation. The quasi-phase matching (QPM) approach uses a periodically modulated nonlinearity that can be achieved by periodically inverting domains in ferroelectric crystals and allows versatile and efficient frequency conversion in the whole transparency region of the material. LÄS MER

  5. 4. Characterization of domain switching and optical damage properties in ferroelectrics

    Författare :Junji Hirohashi; Fredrik Laurell; Ady Arie; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quasi-phase matching; ferroelectric domains; stoichiometric LiNbO3; stoichiometric LiTaO3; KTiOPO4; KNbO3; polarization switching; periodic electric field poling; optical damages; Optical physics; Optisk fysik;

    Sammanfattning : Nonlinear optical frequency conversion is one of the most important key techniques in order to obtain lasers with wavelengths targeted for specific applications. In order to realize efficient and tailored lasers, the quasi-phase-matching (QPM) approach using periodically-poled ferroelectric crystals is getting increasingly important. LÄS MER

  7. 5. Engineering ferroelectric domains and charge transport by proton exchange in lithium niobate

    Författare :Michele Manzo; Katia Gallo; Marin Alexe; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lithium niobate; Ferroelectrics; Teknisk materialvetenskap; Materials Science and Engineering; Fysik; Physics;

    Sammanfattning : Ferroelectrics are dielectric materials possessing a switchable spontaneous polarization, which have attracted a growing interest for a broad variety of applications such as ferroelectric lithography, artificial photosynthesis, random and dynamic access memories (FeRAMs and DRAM), but also for the fabrication of devices for nonlinear optics, etc. All the aforementioned applications rely on the control of the ferroelectric domains arrangement, or the charge distribution and transport. LÄS MER