Side-chain　fluorination　can　enhance　the　backbone　organization　and　carrier　mobility　of　non-fullerene　acceptors　(NFAs)　but　it　often　reduces　their　photovoltage　due　to　the　resulting　deeper-lying　lowest　unoccupied　molecular　orbital　(LUMO)　levels.　Herein,　we　present　a　strategy　to　regulate　the　LUMO　levels　of　two　NFAs,　MC9F5　and　MC7F5,　by　repositioning　the　highly　electronegative　–C2F5　moieties　on　the　side　chains.　This　approach　mitigates　the　impact　of　fluorination　on　the　energy　levels,　thereby　improving　the　photovoltage　and　overall　device　performance.　By　incorporating　10,10,11,11,11-pentafluoro-2-(8,8,9,9,9-pentafluorononyl)undecyl　side　chains,　the　–C2F5　moieties　are　positioned　away　from　the　conjugated　backbone　of　MC9F5,　resulting　in　an　elevated　LUMO　level　compared　with　MC7F5,　which　features　8,8,9,9,9-pentafluoro-2-(6,6,7,7,7-pentafluoroheptyl)nonyl　side　chains.　This　modification　reduces　both　the　charge　generation　and　the　non-radiative　energy　losses　in　the　MC9F5-based　devices.　The　MC9F5-based　small-area　and　minimodule　devices　achieve　efficiencies　of　18.02%　and　15.66%,　respectively,　which　are　among　the　highest　values　reported　for　acceptor–donor–acceptor-type　NFAs.　This　study　highlights　a　valuable　fluorination　strategy　for　achieving　high-performance　NFAs.　©　The　Author(s)　2025.　Published　by　Oxford　University　Press　on　behalf　of　China　Science　Publishing　&　Media　Ltd.