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Full-Text Articles in Engineering
Investigation Of The Synthesis And Optoelectronic Properties Of Ultrasmall Cdse Quantum Dots, Megan Webster
Investigation Of The Synthesis And Optoelectronic Properties Of Ultrasmall Cdse Quantum Dots, Megan Webster
Dissertations and Theses
Traditional, or 1st generation, solar cells have a theoretical upper limit of 33% power conversion efficiency based on the thermodynamic limitation of the single p-n junction cell design. This limitation is known as the Shockley-Queisser limit and methods to design solar cells to circumvent it have been creative, with a significant part of the field focused on quantum dot (QD) based systems. With theoretical efficiencies ranging between 44 and 67% for one sun concentration, QD solar cell designs are clearly superior to the limits of 1st generation solar cells. However, maximum achieved efficiencies for QD-based designs are far …
Microwave Instrumentation And Sensing Techniques For Quantum Efficiency And Minority-Carrier Lifetime Measurements, Kyle Benjamin Lu
Microwave Instrumentation And Sensing Techniques For Quantum Efficiency And Minority-Carrier Lifetime Measurements, Kyle Benjamin Lu
Dissertations and Theses
A non-contact method characterizing the quantum efficiency of a solar cell using the microwave reflectance signature is presented in this thesis. Traditional solar cell quantum efficiency (QE) measurements are only possible near the completion of the fabrication process using contacts in direct physical connection with the metalized surface tabs to probe and extract charge carriers from the device. However, pressure within the solar metrology industry to report the spectral performance of the device earlier in the manufacturing process as part of the process control loop requires that a new non-contact method be developed. This thesis work contributes the development of …
The Effects Of Phosphonic Acids In Dye-Sensitized Solar Cells, Keith Edward James
The Effects Of Phosphonic Acids In Dye-Sensitized Solar Cells, Keith Edward James
Dissertations and Theses
Novel methods for the construction of dye-sensitized solar cells (DSSCs) were developed. A thin dense underlayer of TiO2 was applied on fluorine-doped tin oxide (FTO) glass using as a precursor Tyzor AA-105. Subsequently a mesoporous film of P-25 TiO2 was applied by spreading a suspension uniformly over the surface of the underlayer and allowing the plate to slowly dry while resting on a level surface. After sintering at 500° C slides were treated with TCPP as a sensitizing dye and assembled into DSSCs. A novel method was used to seal the cells; strips of Parafilm® were used as …
Effect Of Ionic Liquid Electrolytes In Dsscs With Titanium Dioxide (Tio2) Inverse Opal Structures, Naomi S. Ramesar
Effect Of Ionic Liquid Electrolytes In Dsscs With Titanium Dioxide (Tio2) Inverse Opal Structures, Naomi S. Ramesar
Dissertations and Theses
Dye-sensitized solar cells (DSSC) are low-cost alternatives to conventional solar cells that can work well in low-light conditions. Despite considerable study on improving the efficiency of DSSCs, the current liquid electrolyte cell has plateaued at a conversion efficiency of ~ 12%. A major problem with these cells regarding their applicability is the low viscosity and high volatility of the toxic electrolyte, i.e., acetonitrile, which cause leakage and volatilization. We propose that using ionic liquids (ILs), which are more viscous, less volatile, and conductive, may be more suitable electrolytes. However, one unwanted side effect of the higher viscosity of the ILs …
Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah
Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah
Dissertations and Theses
We report on the fundamental properties and device applications of semiconductor nanoparticles. ZnO nanowires and CdSe quantum dots were used, prepared, characterized, and assembled into novel light-emitting diodes and solar cells. ZnO nanowire films were grown electrochemically using aqueous soluble chloride-based electrolytes as precursors at temperatures below 90° C. Dopants were added to the electrolyte in the form of chloride compounds, which are AlCl3, CoCl2, CuCl2, and MnCl2. The optical, magnetic, and structural properties of undoped and transition-metal-ion doped ZnO nanowires were explored. Our results indicate that the as-grown nanowire structures have …