Search for: All records

Dye-sensitized solar cells (DSSCs) hold unique promise in solar photovoltaics owing to their low-cost fabrication and high efficiency in ambient conditions. However, to improve their commercial viability, effective, and low-cost methods must be employed to enhance their light harvesting capabilities, and hence photovoltaic (PV) performance. Improving the absorption of incoming light is a critical strategy for maximizing solar cell efficiency while overcoming material limitations. Mesoporous silica nanoparticles (MSNs) were employed herein as a reflective layer on the back of transparent counter electrodes. Chemically synthesized MSNs were applied to DSSCs via bar coating as a facile fabrication step compatible with roll-to-roll manufacturing. The MSNs diffusely scatter the unused incident light transmitted through the DSSCs back into the photoactive layers, increasing the absorption of light by N719 dye molecules. This resulted in a 20% increase in power conversion efficiency (PCE), from 5.57% in a standard cell to 6.68% with the addition of MSNs. The improved performance is attributed to an increase in photon absorption which led to the generation of a higher number of charge carriers, thus increasing the current density in DSSCs. These results were corroborated with electrochemical impedance spectroscopy (EIS), which showed improved charge transport kinetics. The use of MSNs as reflectors proved to be an effective practical method for enhancing the performance of thin film solar cells. Due to silica’s abundance and biocompatibility, MSNs are an attractive material for meeting the low-cost and non-toxic requirements for commercially viable integrated PVs. 

Mesoporous silica nanoparticles (MSNs) are highly porous carriers used in drug and gene delivery research for biomedical applications due to their high surface area, narrow particle size distribution, and low toxicity. Incorporating disulfide (SS) bonds into the walls of MSNs (MSN-SSs) offers a dual pathway for drug release due to the pore delivery and collapsing porous structure after cellular engulfment. This study explores the effect of embedding disulfide bonds into MSNs through various structural and biological characterization methods. Raman spectroscopy is employed to detect the SS bonds, SEM and TEM for morphology analyses, and a BET analysis to determine the required amount of SSs for achieving the largest surface area. The MSN-SSs are further loaded with doxorubicin, an anticancer drug, to assess drug release behavior under various pH conditions. The MSN-SS system demonstrated an efficient pH-responsive drug release, with over 65% of doxorubicin released under acidic conditions and over 15% released under neutral conditions. Cleaving the SS bonds using dithiothreitol increased the release to 94% in acidic conditions and 46% in neutral conditions. Biocompatibility studies were conducted using cancer cells to validate the engulfment of the nanoparticle. These results demonstrate that MSN-SS is a feasible nanocarrier for controlled-release drug delivery.