Sökning: "photoconductivity"
Visar resultat 1 - 5 av 12 avhandlingar innehållade ordet photoconductivity.
1. Optical Studies of InAs Quantum Dots in III-V Semiconductors
Sammanfattning : 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. LÄS MER
2. Functional Metal Oxide Materials Deposited by Inkjet Printing Technique
Sammanfattning : 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. LÄS MER
3. Preparation and Characterization of Lead Halide Perovskites : Towards sustainable, cost-effective and upscalable solar cell manufacture
Sammanfattning : 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. LÄS MER
4. Modelling Band Gap Gradients and Cd-free Buffer Layers in Cu(In,Ga)Se2 Solar Cells
Sammanfattning : 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. LÄS MER
5. Defect Induced Room-Temperature Ferromagnetism in ZnO and MgO Thin FIlms and Device Development
Sammanfattning : 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. LÄS MER