Organic solar cell research has developed during the past 30 years, but especially in the last decade it has attracted scientific and economic interest triggered by a rapid increase in power conversion efficiencies. This was achieved by the introduction of new materials, improved materials engineering, and more sophisticated device structures. Today, solar power conversion efficiencies in exces...

Enormous progress has been made in recent years on a number of photovoltaic (PV) materials and devices in terms of conversion efficiencies. Ultrahigh-efficiency (>30%) PV cells have been fabricated from gallium arsenide (GaAs) and its ternary alloys such as gallium indium phosphide (GaInP2). The high-efficiency GaAsbased solar cells are being produced on a commercial scale, particularly for spa...

In lead halide perovskite solar cells, there is at least one recycling event of electron-hole pair to photon to electron-hole pair at open circuit under solar illumination. This can lead to a significant reduction in the external photoluminescence yield from the internal yield. Here we show that, for an internal yield of 70%, we measure external yields as low as 15% in planar films, where light...

Laboratory demonstrations of spontaneous photoelectrochemical (PEC) solar water splitting cells are reviewed. Reported solar-to-hydrogen (STH) conversion efficiencies range from o1% to 18%. The demonstrations are categorized by the number of photovoltaic junctions employed (2 or 3), photovoltaic junction type (solid–solid or solid–liquid) and the ability of the systems to produce separated reac...

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...

Second-harmonic generation using the type-II polarization configuration is demonstrated in quasi-phase-matched GaAs radicalAlGaAs superlattice waveguides. Phase-matching wavelengths and conversion efficiencies were determined for several quasi-phase-matching periods using 1.9 ps pulses. Saturation effects at high input power were concluded to be the result of third-order nonlinear effects.

We report a new class of anthracene-thiophene-based copolymers, PAT4. The UV-vis absorption spectrum of PAT4 was broad and covered the full range of the solar spectrum. The hole mobility of PAT4 was high, up to 0.037 cm(2) V(-1) s(-1). PAT4-based organic solar cells showed promising power conversion efficiencies of 1.7%.