Search for dissertations about: "photoconductivity"

Showing result 1 - 5 of 12 swedish dissertations containing the word photoconductivity.

2. 1. Optical Studies of InAs Quantum Dots in III-V Semiconductors

   Author : Lars Landin; Fasta tillståndets fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum dots; III-V semiconductors; k.p calculations; photoluminescence; deep-level transient spectroscopy; photoconductivity; few particle effect; single dot spectroscopy; InAs InP; Semiconductory physics; Halvledarfysik; Fysicumarkivet A:2000:Landin; InAs GaAs;

   Abstract : I this thesis, optical studies of InAs quantum dots (QDs) in GaAs and InP are presented. The electronic structure of these zero dimensional structures, grown in the Stranski-Krastanow growth mode, was studied by photoluminescence spectroscopy (PL), junction space-charge techniques (JSCT) and photoconductivity (PC) measurements. READ MORE

4. 2. Functional Metal Oxide Materials Deposited by Inkjet Printing Technique

   Author : Yan Wu; Lyubov Belova; Gillian Gehring; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Inkjet printing; photoconductivity; ZnO; Al-ZnO; composite; electron transfer; CdS; field effect transistor; photosensitive; RT do-ferromagnetism; Mn-doped ZnO; MgO; Materials science; Teknisk materialvetenskap;

   Abstract : This thesis presents a comprehensive study of the intrinsic room temperature ferromagnetism in 85 to 100nm thin films produced by in situ deposition of industrially important pristine MgO and ZnO by inkjet printing. It is suggested that the observed long range magnetic order, the so-called do magnetism in these oxides arises from cation vacancies. READ MORE

5. 3. Preparation and Characterization of Lead Halide Perovskites : Towards sustainable, cost-effective and upscalable solar cell manufacture

   Author : Kári Sveinbjörnsson; Erik Johansson; Pablo Docampo; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perovskite solar cells; perovskite; photoconductivity; carbon nanotubes; transparent contact; ambient processing; water-based; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

   Abstract : The perovskite solar cell (PSC) is a recent contender within the photovoltaic research field. In a matter of a few years, the power conversion efficiency (PCE) of the PSC has catapulted from 4% to above 22%, which represents one of the fastest developments in the field. READ MORE

6. 4. Modelling Band Gap Gradients and Cd-free Buffer Layers in Cu(In,Ga)Se2 Solar Cells

   Author : Jonas Pettersson; Charlotte Platzer-Björkman; Marika Edoff; Marc Burgelman; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; CIGS; Thin film solar cells; Electrical modelling; Alternative buffer layers; Gallium gradients; Simulations; Electrical characterization; Metastabilities; Light-soaking; Hall measurements; Persistent photoconductivity; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

   Abstract : A deeper understanding of Cu(In,Ga)Se2 (CIGS) solar cells is important for the further improvement of these devices. This thesis is focused on the use of electrical modelling as a tool for pursuing this aim. Finished devices and individual layers are characterized and the acquired data are used as input in the simulations. READ MORE

7. 5. Defect Induced Room-Temperature Ferromagnetism in ZnO and MgO Thin FIlms and Device Development

   Author : Mukes Kapilashrami; Lyuba Belova; E Dan Dahlberg; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Room-temperature ferromagnetism; intrinsic defects; un-balanced balanced magnetron sputtering; magnetic anisotropy and photoconductivity; Materials science; Teknisk materialvetenskap;

   Abstract : This thesis presents the discovery of defect induced room-temperature ferromagnetism in industrially important ZnO and MgO thin films, and establishes from a systematic study, in both ZnO and MgO films, the unique phenomenon of the sequences of transitions from ferromagnetism to para-, and eventually the well known diamagnetism of the bulk as a function of film thickness. Highly oriented and high quality dense thin films of ZnO and MgO have been deposited by reactive (balanced) magnetron sputtering under different ambience conditions and deposition temperatures. READ MORE