Dye-sensitized solar cells (DSCs) are currently attracting considerable attention because of their high light-to-electricity conversion efficiencies, ease of fabrication, and low production costs. Many recent efforts have been devoted to the development of new and efficient sensitizers that are suitable for practical use. Among the investigated compounds, ruthenium sensitizers have been disting...

This paper presents a practical variation of extremum seeking (ES) that guarantees asymptotic convergence through a Lyapunov-based switching scheme (Lyap-ES). Traditional ES methods enter a limit cycle around the optimum. Lyap-ES converges to the optimum by exponentially decaying the perturbation signal once the system enters a neighborhood around the extremum. As a case study, we consider maxi...

This paper gives recent results of experiments with a coaxial Plasma-Pulse-Accelerator (PPA). Discharging a capacitor bank into the PPA more than 80 % of the stored energy could be transferred from the electrical circuit into the plasma. Accelerating masses of 10 g to velocities of 1020 m/s overall efficiencies of 22 % were achieved. A 3 g mass could be accelerated in the same PPA to 2000 m/s; ...

For a dye-sensitized solar cell with a near-infrared squaraine (SQ1) sensitizer, the photovoltaic performance was enhanced remarkably with a reflective luminescent down-shifting (R-LDS) layer to increase the light-harvesting efficiency at the wavelength region 400-550 nm where the SQ1 dye has weak absorption. Relative enhancements greater than 200% in IPCE near 500 nm and 40-54% in JSC were ach...

In situ grown nickel sulfide and cobalt sulfide hierarchical nanospheres on F-doped SnO2 (FTO) substrates exhibited comparable catalytic activities to sputtering Pt on the counter electrodes for dye-sensitized solar cells (DSSCs). The fresh cells with the nickel sulfide and cobalt sulfide on the counter electrodes could reach power conversion efficiencies of 6.81% and 6.59% respectively, approa...

Organo-metal halide perovskite–based solar cells have been the focus of intense research over the past five years, and power conversion efficiencies have rapidly been improved from 3.8 to >21%. This article reviews major advances in perovskite solar cells that have contributed to the recent efficiency enhancements, including the evolution of device architecture, the development of material depo...

We demonstrate numerically a 2-D nanostructured design for light trapping in a low band-gap polymer solar cell. Finite element method simulations are used to study the effect of varying nanostructure periodicity, height, and shape on active layer absorption. Maintaining a constant active layer thickness of 100 nm we observe an enhancement in solar absorption of almost 40% relative to a planar c...

We report here the synthesis, electrochemical and photophysical properties of a series of novel exTTF-based organic dyes (3 and 7a,b) as well as their application in dye-sensitized solar cells (DSSCs). In the three designed dyes, the electron-donor exTTF group is connected to the rhodanine-3-acetic acid electron-acceptor unit through vinyl or vinyl-thiophene spacers. The electrochemical studies...

The synthesis and characterization of bis(difluoroboryl)-1,2-bis((1H-pyrrol-2-yl)methylene)hydrazone functionalized with two lateral vinyl-thienyl modules and exhibiting strong absorption in the 400-800 nm window in thin films are reported. Bulk heterojunction solar cells assembled with these dyes and a fullerene derivative (PC71BM), using very small quantities of the additive diiodooctane, giv...

Solution processed silver nanowire meshes (Ag NWs) were laminated on top of solid-state dye-sensitized solar cells (ss-DSCs) as a reflective counter electrode. Ag NWs were deposited in <1 min and were less reflective compared to evaporated Ag controls; however, AgNW ss-DSC devices consistently had higher fill factors (0.6 versus 0.69), resulting in comparable power conversion efficiencies (2.7%...