biostudies-literatureLiu XDepartment of Science and Technology, Hubei Provincial People's GovernmentDepartment of Science and Technology, Hubei Provincial People's Governmente2402158https://www.ebi.ac.uk/biostudies/studies/S-EPMC11462292biostudies-literatureUnknown11(37)Sol-gel processed zinc oxide (ZnO) is one of the most widely used electron transport layers (ETLs) in inverted organic solar cells (OSCs). The high annealing temperature (≈200 °C) required for sintering to ensure a high electron mobility however results in severe damage to flexible substrates. Thus, flexible organic solar cells based on sol-gel processed ZnO exhibit significantly lower efficiency than rigid devices. In this paper, an indium-doping approach is developed to improve the optoelectronic properties of ZnO layers and reduce the required annealing temperature. Inverted OSCs based on In-doped ZnO (IZO) exhibit a higher efficiency than those based on ZnO for a range of different active layer systems. For the PM6:L8-BO system, the efficiency increases from 17.0% for the pristine ZnO-Advanced science (Weinheim, Baden-Wurttemberg, Germany)In-Doped ZnO Electron Transport Layer for High-Efficiency Ultrathin Flexible Organic Solar Cells.PMC114622922023BAB109Ren XXia ZZhang DZhu YLiao XHuang HCheng YLiu XYang XJiang ZRen LTan WHuang WLu JJi YMcNeill CfalseIn-Doped ZnO Electron Transport Layer for High-Efficiency Ultrathin Flexible Organic Solar Cells.Sol-gel processed zinc oxide (ZnO) is one of the most widely used electron transport layers (ETLs) in inverted organic solar cells (OSCs). The high annealing temperature (≈200 °C) required for sintering to ensure a high electron mobility however results in severe damage to flexible substrates. Thus, flexible organic solar cells based on sol-gel processed ZnO exhibit significantly lower efficiency than rigid devices. In this paper, an indium-doping approach is developed to improve the optoelectronic properties of ZnO layers and reduce the required annealing temperature. Inverted OSCs based on In-doped ZnO (IZO) exhibit a higher efficiency than those based on ZnO for a range of different active layer systems. For the PM6:L8-BO system, the efficiency increases from 17.0% for the pristine ZnO-2024-01-01T00:00:00Z2024 Oct2026-07-14T19:42:01.101Z2025-04-04T01:14:45.591ZS-EPMC114622923892328010.1002/advs.202402158