Abstract: The invention relates to the use, in the manufacturing of materials or devices for photonic applications, of chalcogenide-type compounds having an octahedrally coordinated indium element and wherein a transition element is introduced in octahedral position generating a partially occupied intermediate band separate from those of valence and conduction of the initial semiconductor, according to quantum mechanics calculations. This enables, by absorption of two photons having energy lower than the prohibited bandwidth of the initial semiconductor, a result equivalent to that achieved, without said intermediate band, by the absorption of a higher-energy photon. The use of such a material can thereby improve yield and performance of various photovoltaic, photocatalytic, photoelectrochemical, optoelectronic or photonic conversion devices. Indium sulfide substituted in part with vanadium or titanium is one of the specific materials having these properties that is synthesised according to the invention.

Abstract: The invention relates to a solar cell containing a semiconductor (1) with an intermediate band (2) that is half filled with electrons, located between two layers of ordinary n type (3) and p type (4) semiconductors. When lighted, electron-hole pairs are formed either by a photon that absorbs the necessary energy (5) or by two photons (6,7) that absorb less energy which pump an electron from the valence band to the intermediate band (8) and from the latter to the conductance band (9). An electrical current is generated that exits on the p side and returns via the n side. The n and p layers also prevent the intermediate band from contacting the outer metal connections, which would have resulted in a short-circuit. Said cell converts solar energy into electricity in a more efficient manner than conventional cells and contributes to improvement of the photovoltaic devices.