Phys.org October 22, 2024 The photovoltaic effect can occur without metal/semiconductor or semiconductor/semiconductor interfaces in materials with spontaneous electric polarization due to a lack of spatial inversion symmetry known as bulk photovoltaic (BPV) effect which facilitates photoelectric conversion. Researchers in Japan reported an experimental demonstration of the BPV effect in α-In2Se3 films along the out-of-plane direction by using graphite films as transparent electrodes. A short-circuit current was detected under white light irradiation, and the sign was inverted upon inverting the direction of electric polarization, thus suggesting its origin to be the shift current, distinct from the effect occurring at the […]
Tag Archives: Photovoltaics
Light momentum turns pure silicon from an indirect to a direct bandgap semiconductor
Phys.org September 20, 2024 Photons do not carry sufficient momentum to induce indirect optical transitions in semiconducting materials, such as silicon, necessitating the assistance of lattice phonons to conserve momentum. Therefore, silicon is a less attractive material for a wide variety of optoelectronic applications. An international team of ranchers (Russia, Israel, USA – UC Irvine) introduced an alternative strategy to fulfill the momentum-matching requirement in indirect optical transitions. They demonstrated that when confined to scales below ∼3 nm, photons acquired sufficient momentum to allow electronic transitions at the band edge of Si without the assistance of a phonon. Confined photons […]
A solar cell you can bend and soak in water
RIKEN Research March 27, 2024 Waterproofing ultra flexible organic photovoltaics without compromising mechanical flexibility and conformability remains challenging. An international team of researchers (Japan, USA – Georgia Institute of Technology) demonstrated waterproof and ultra flexible organic photovoltaics through the in-situ growth of a hole-transporting layer to strengthen interface adhesion between the active layer and anode by depositing silver electrode directly on top of the active layers, followed by thermal annealing treatment. The in-situ grown hole-transporting layer exhibited higher thermodynamic adhesion between the active layers, resulting in better waterproof. The 3 μm-thick organic photovoltaics retained 89% and 96% of their pristine performance […]
Outstanding organic solar cells’ performance achieved by using new technology
EurekAlert June 23, 2021 Although the organic photovoltaic (OPV) elements are lighter, more flexible, and cheaper to produce, their efficiency still falls behind that of other photovoltaic technologies. An international team of researchers (Saudi Arabia, Lithuania, Greece) synthesised a material, which self-assembles into a monolayer that can cover a variety of surfaces and function as a hole-transporting layer in a solar element. They made some modifications in the material used in self-assembling molecular-thin layer (SAM) formation to tailor it for organic solar elements. The organic solar cell using Br-2PACz molecule-thin coating as a hole-transporting layer achieved a power conversion efficiency […]