Solar-energy conversion usually takes one of two forms: the 'quantum' approach, which uses the large per-photon energy of solar radiation to excite electrons, as in photovoltaic cells, or the 'thermal' approach, which uses concentrated sunlight as a thermal-energy source to indirectly produce electricity using a heat engine. Here we present a new concept for solar electricity generation, photon...

We have generated 201 W of green (514.5 nm) average power from a frequency-doubled picosecond cryogenic Yb:YAG laser system driven by a 50 MHz, 12.4 ps mode-locked Yb fiber laser producing 430 W of average power at 1029 nm, using direct pulse amplification. The fundamental beam produced was near-diffraction-limited (M(2)<1.3). Second-harmonic-generation is achieved using a 20 mm long noncritica...

Two new star-shaped organic materials have been applied as ternary components in solar cells to give greater light transparency with only a small sacrifice power conversion efficiencies.

Dimer and trimer analogues of Spiro-OMeTAD are porous hole transport materials with improved conductivity compared to the parent material give higher power conversion efficiencies in perovskite solar cells.

The conversion efficiency of geothermal power developments is generally lower than that of conventional thermal power plants. Confusion can be found in literature concerning the estimation of this conversion efficiency. Geothermal power plants conversion efficiency estimates that is based on the enthalpy of the produced geothermal fluid can be the most desirable for use during the first estimat...

Dye-sensitized solar cells (DSSCs) have emerged as an innovative solar energy conversion technology which provides a pathway for the development of cheap, renewable and environmentally acceptable energy production (Gledhill, Scott et al., 2005; O'Regan & Grätzel, 1991; Shaheen, Ginley et al., 2005). A typical DSSC consists of a sensitizing dye chemically anchored to a nanocrystalline wide band ...

This paper describes a novel boost converter to be used with energy harvesters that provide only low output voltages. The device is self-supplied from electric power delivered to its input. With peak power conversion efficiencies above 30% at start-up voltages down to 10 mV this circuit sets best values in comparison with the state-of-the-art. This is achieved by the novel combination of a Meis...

The trade-off between the short-circuit current density (JSC) and open-circuit voltage (VOC) has been one of largest challenges in improving power conversion efficiencies (PCEs) organic solar cells...