TECHNOLOGY FOCUS - ELECTRONICS - Preferred Device: In the device, the external luminescent plate is configured so as to absorb a part of incident radiation having a frequency in the ultraviolet field, and emit a first radiation to the semiconductor layer at a frequency such as to produce photoelectric effect. The internal luminescent plate is configured so as to absorb a part of incident radiation having a frequency in the infrared field, and emit a second radiation to the semiconductor layer at a frequency such as to produce photoelectric effect. The nanostructured semiconductor layer has a horseshoe-type configuration, comprising an external portion of P-doped silicon having a substantially upturned U-like shape, and an internal portion of N-doped silicon. Conveying means comprises a conveyor arranged along the external periphery of the ring and having a triangular section, having a first face appendage of the external luminescent plate along the peripheral receiving surface and a second face configured to gather and convey the incident radiation. The conveyor has an isosceles right-angled triangle section, comprising a third mirror-fitted oblique face, opposite to the first and second face. It is made of polymethyl methacrylate, obtainable from a mixture of plexit 55 combined with a layer of PE 399 Kristalflex or other anti-reflex film onto its receiving face. The conveying means comprises one or more Fresnel-type lenses, overlapped to and spaced apart from the conveyor and arranged so as to concentrate the luminous radiation incident to the latter. The photovoltaic device comprises four Fresnel lenses, arranged so as to form a circle in which each lens takes up a respective quadrant, each Fresnel lens being apt to concentrate the incident radiation at the respective second face portion subjected thereto of the conveyor. External and internal luminescent plates are made of polymethyl methacrylate, obtainable from a mixture of plexit 55. The external luminescent plate comprises a pair of external reflecting strips arranged each along a respective oblique side. Internal luminescent plate comprises a pair of internal reflecting strips arranged each along a respective oblique side and a reflecting strip arranged along the minor base of the trapezoidal section. External and internal luminescent plates internally comprise pigments apt to produce a phosphorescent effect. The pigments are of yellow-green type. The photovoltaic device comprises four hemispheric covers, each arranged on a respective side of the ring. It further comprises a cooling system associated to the solar concentrator. The cooling system comprises one or more cooling channels provided with coolant. Cooling channels are obtained inside the hemispheric covers. The photovoltaic device comprises a container inside which it is inserted and supported, the container being closed topwise by the four Fresnel lenses arranged in circle. It comprises a sun-following moving system.