Energy Materials & Technology
Shawqi Al Dallal; Khalil Ebrahim Jasim
Abstract
Third generation solar cells, such as dye and quantum dot sensitized solar cells are attracting attention of many research groups. In this investigation we explore the role of dye extract on the enhancement of the photovoltaic properties of quantum dot sensitized solar cells (QDSSCs). Lead sulfide quantum ...
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Third generation solar cells, such as dye and quantum dot sensitized solar cells are attracting attention of many research groups. In this investigation we explore the role of dye extract on the enhancement of the photovoltaic properties of quantum dot sensitized solar cells (QDSSCs). Lead sulfide quantum dots of different sizes have been used to sensitize a nanostructured titanium oxide electrode. We compare the open circuit voltage, the short circuit current, and power conversion efficiency of QDSSCs with the same quantities as obtained for dye-enhanced system using pomegranate dye extract. An open circuit voltage of 166 mV, a short circuit current of 0.1 mA, and an efficiency of 0.32% were obtained for 2.4 nm radius lead sulfide quantum dot sensitized solar cells. Using pomegranate dye extract reveals a considerable enhancement of the above characteristics. The combined dye-quantum dot system produces an open circuit voltage of 300 mV, a short circuit current of 0.55 mA, and an efficiency of 3.4%. For 3.2 nm radius QDs, the efficiency is substantially higher, reaching about 7%. A model describing the structure and processes leading to the above enhancement of the assembled solar cell characteristics is presented. In this model we explain the interplay between the transfer of electrons between the dye, quantum dots, and subsequent injection in the wide band gap titanium dioxide semiconductor.
Sandeep Kumar; Neeraj Dilbaghi;Anju Manuja; Gaurav Bhanjana
Abstract
Nanoparticles are being designed with chemically modifiable surfaces to attach a variety of molecules to improve biosensing, imaging techniques, delivery vehicles, and other useful biological tools. Keeping this in view, the present research work is focused on investigation of cytotoxicity of metal oxide ...
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Nanoparticles are being designed with chemically modifiable surfaces to attach a variety of molecules to improve biosensing, imaging techniques, delivery vehicles, and other useful biological tools. Keeping this in view, the present research work is focused on investigation of cytotoxicity of metal oxide nanoparticles. Different metal oxide nanoparticles (e.g titanium dioxide, zinc oxide, iron oxide, aluminum oxide etc) of different sizes and different concentrations were used to investigate the cellular response. Electron microscopy and colorimetric assays were used to characterize the various process steps. Zirconium oxide nanoparticles were used in suspension form stabilized with stabilizer and the others were used as their aqueous suspension. Results clearly reflect that as the concentration increases, cytotoxicity also increases. As aggregation occurs, cytotoxicity decreases. In suspension with stabilizer, cytotoxicity is more as compared to aqueous suspensions.
