Since their introduction, dye-sensitized solar cells (DSCs) have achieved huge success at a laboratory level. Recently, research is concentrated to visualize large DSC modules at the commercial platform. In that aspect, we have tested structurally simple porphyrin-based dye SK6 and anthracene-based dye CW10 for DSCs application under simulated 1 sun (AM 1.5G) and indoor light sources. These two dyes can be easily synthesized and yet are efficient with cell performances of ca. 5.42% and ca. 5.75% (without coadsorbent/additive) for SK6 and CW10, respectively, under AM 1.5G illumination. The power conversion efficiency (PCE) of SK6 reported in this work is the highest ever reported; this is achieved by optimizing the adsorption of SK6 on TiO photoanode using the most suitable solvent and immersion period. Cosensitization of SK6 with CW10 on TiO surface has boosted cell performance further and achieved PCE of ca. 6.31% under AM 1.5G illumination. Charge-transfer properties of individual and cosensitized devices at TiO/dye/electrolyte interface were examined via electrochemical impedance spectroscopy. To understand the cell performances under ambient light conditions, we soaked individual and cosensitized devices under T5 and light-emitting diode light sources in the range of 300-6000 lx. The PCE of ca. 22.91% under T5 light (6000 lx) with J = 0.883 mA cm, V = 0.646 V, and FF = 0.749 was noted for the cosensitized device, which equals a power output of 426 μW cm. These results reveal that DSCs made of structurally simple dyes performed efficiently under both 1 sun (AM 1.5G) and indoor light conditions, which is undoubtedly a significant achievement when it comes to a choice of commercial application.

An electrostatic particle-in-cell simulation code is developed to investigate the interaction between plasma and material surfaces in the presence of secondary electron emission. Kinetic ions are included into the numerical simulation to incorporate the process of ion bombardment on the material surfaces. The influences of the secondary electron emission on sheath dynamics are further investigated, which is induced by ions on top of electrons.Index Terms-Kinetic ions, particle-in-cell (PIC) simulation, plasma-material surface interaction, secondary electron emission.

Suppression of charge recombination is an efficient strategy capable of improving the photovoltaic performance of dye-sensitized solar cells (DSSCs). Herein, we fabricate a Nb 2 O 5 thin film on a fluorine-doped tin oxide (FTO) photoanode using a facile dip-coating method and study its blocking effect on charge recombination under various illuminance. The results show that the blocking effect of Nb 2 O 5 is strongly illuminance intensity dependent. The blocking effect of Nb 2 O 5 is insignificant at strong (one sun, >100,000 lux) illumination because the suppressed reverse charge flux makes no substantial contribution to the high-level injection of photo-excited charges. Conversely, the blocking effect plays an important role in the efficiency improvement as the photon-injected charge flux significantly reduces at low-intensity illumination (300-6000 lux). The efficiency of DSSCs with a blocking layer can be improved by 10% to 53% under low-intensity illumination, and the efficiency improvement is attributed to an improvement in fill factor.