Sökning: "carrier recombination"
Visar resultat 16 - 20 av 66 avhandlingar innehållade orden carrier recombination.
16. Light Induced Charge Generation, Recombination, and Transport in Organic Solar Cells
Sammanfattning : Light-to-electricity conversion processes in organic and dye sensitized solar cells have attracted much scientific effort, aiming to understand the fundamental nature of these processes and to improve solar cell efficiency. Power conversion efficiency of such solar cells has progressed steadily in the last few decades, suggesting applicability for commercial products in the nearest future. LÄS MER
17. Optical studies of carrier transport and fundamental absorption in 4H-SiC and Si
Sammanfattning : The Fourier transient grating (FTG) technique and a novelspectroscopic technique, both based on free carrier absorption(FCA) probing, have been applied to study the carrierdiffusivity in 4H-SiC and the fundamental absorption edge in4H-SiC and Si, respectively. FTG is a unique technique capable of detecting diffusioncoefficient dependence over a broad injection interval rangingfrom minority carrier diffusion to the ambipolar case. LÄS MER
18. Spectroscopic studies of doped GaAs/ AlGaAs quantum wells in the high carrier density regime
Sammanfattning : This thesis is mainly based on experimental and theoretical investigations of the electronic structures and optical properties of p-type doped GaAs/AlGaAs quantum wells using a combination of photoluminescence and magneto-optical spectroscopy in the presence of high magnetic fields.The effects of high hole densities up to 3. LÄS MER
19. Optical properties of GaN and InGaN studied by time- and spatially-resolved spectroscopy
Sammanfattning : The past decade has seen rapid expansion in the use of group III-nitride based devices. White InGaN LEDs are substituting incandescent light bulbs, space satellite industry adopting ion-radiation-resistant GaN transistors, and AlGaN deep UV LEDs are increasingly being used for water disinfection and air purification. LÄS MER
20. Phase Modulation Two-Photon Microscopy of Hybrid Halide Perovskite
Sammanfattning : Recently, intense research activities have been focused on solution-processed hybrid lead halide perovskite semiconductors which are being developed for the solar-cell, light emitting diode (LED), and lasing applications. To optimize and fabricate a competitive perovskite-based optoelectronic device, the fundamental studies of the electronic structure, photo-generated carrier dynamics as well as the photoluminescence (PL) & photocurrent (PC) response are necessary and of great significance. LÄS MER
