Experimental validation and numerical assessment of 4 T spectral-splitting photovoltaic tile with unconventional bifacial capabilities and minimized shading
Year: 2026
Authors: Morabito F., Piliougine M., Fontani D., Farina A., Lombardo SA., Pietralunga SM.
Autors Affiliation: CNR, IFN, Piazza Leonardo Vinci 32, I-20133 Milan, Italy; CNR, IMM, Zona Ind,Ottava Str 5, I-95121 Catania, Italy; CNR, INO, Largo Enrico Fermi 6, I-50125 Florence, Italy.
Abstract: Recently, photovoltaic solar modules have been proposed as both functional and aesthetic architectural elements. Building-integrated and vehicle-integrated photovoltaics require maximizing power per unit area, suitability to complex holding structures and design compatibility, leading to solutions beyond conventional architectures. In this work, we present the experimental validation of a proof-of-concept prototype of a four-terminal photovoltaic tile, whose optical core is based on a right-angled wedge coupled with dichroic mirrors, guiding the visible radiation to a gallium arsenide (GaAs) cell and the infrared radiation to a bifacial silicon (Si) cell. While providing independent spectral and electrical operation of each solar cell, our novel proposal boosts bifacial efficiency, by fostering albedo collection and by minimizing self-shading. Outdoor tests show improved albedo collection at low solar elevation and consistent values of power conversion efficiency (PCE) normalized to input irradiance, pointing to stability and reliability of installation. We consider commercial solar cells at 20% and 24% PCE, respectively for the GaAs and Si. Solar generators, using ideally performing bifacial tiles aligned in multiple rows and electrically connected, are estimated to globally exceed 30% in PCE, at ground coverage ratios as high as 86%. These results validate the proposed concept and route the pathway to optimized prototypes. Among the many advantages we list low supports, which ensure low visual impact, lightweight and possibly cost-reduction, and a 4-terminal and spectral-splitting configuration at optimal land usage. In perspective, it appears attractive as an active element in design-driven integrated photovoltaics, to overcome the theoretical limitation of silicon-based photovoltaic technology.
Journal/Review: SOLAR ENERGY
Volume: 317 Pages from: 114983-1 to: 114983-10
More Information: This work was co-funded by: Project CNR-UVR AMICO2_PoC, Next Generation EU, Italy PoC 2022-PNRR MIMIT-UIBM M1 C2 I6; IPCEI Micro-elettronica 2, project MicroTech_for_Green; IPHOQS Infrastr ucture Integrated Infrastructure Initiative in Photonic and Quantum Sciences (IR0000016, CUPB53C22001750006); Research Infrastructure Beyond-Nano co-funded by Regione Sicilia (D.D.G. 2929/5S) and by MUR (Decree 2510/2019).KeyWords: Bifacial photovoltaics; Four terminals; Low concentration photovoltaics; Spectral splittingDOI: 10.1016/j.solener.2026.114983
