Seoane Iglesias, NataliaFernández Fernández, EduardoAlmonacid, FlorenciaGarcía Loureiro, Antonio Jesús2025-01-202025-01-202020-11-261099-159Xhttps://hdl.handle.net/10347/38770The efficiency of solar cells can be enhanced by increasing the light intensity and/or the number of bandgaps of the structure. However, current solar cells cannot fully exploit these two factors because of various critical drawbacks. Here, we show a novel microscale, that is, side ≈ 0.5 mm, vertical solar cell structure that does not suffer the series resistance and bandgap limitations issues of current devices. The preliminary structures investigated show extreme efficiencies, >40%, at ultrahigh concentration factors of 15 000 suns. In addition, future designs with a better bandgap configuration are expected to deliver cells with efficiencies far above 50% at extreme light intensities. This early design offers a fast and reliable route to push the efficiency towards the maximum solar conversion limit and represents a promising way to develop new-generation ultraefficient and low-cost concentrator photovoltaic systems.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Vertical solar cellsIntrinsic semiconductorsMicro-scalingConcentrator photovoltaicsUltra-high light intensities3322 Tecnología energéticajournal article10.1002/pip.3369open access