<p>The anti-reflective film is one of the important and economical ways to improve the photoelectric conversion efficiency of solar cells. To enhance the weatherability of sol-gel derived SiO₂ antireflection films, a hybrid silicon source system consisting of isobutyl triethoxysilane (IBTS) and tetraethyl orthosilicate (TEOS) was employed for fabricating porous anti-reflection coatings via dip-coating, using polyethylene glycol monomethyl ether (mPEG) as the pore-forming agent. This study systematically investigated the influence of IBTS concentration on the film’s structural and optical properties. The results revealed a non-monotonic dependence of both film porosity and optical transmittance on IBTS content, with optimal performance achieved at intermediate concentrations. When the amount of IBTS was 6 ml, the film’s average transmittance within 380–1100 nm wavelength range reached the maximum 93.61%, 4.4 percentage points higher than that of the glass substrate. Moreover, the film’s adhesion strength reached grade 0, and its hardness was greater than 9 H. When the coated glass was used as the cover instead of the substrate glass, the efficiency of monocrystalline silicon solar cells improved from 11.64% to 12.26%, a relative increase of 4.93%. The film’s hardness and adhesion strength changed little after 100 h of UV lamp irradiation, while the average transmittance in the range of 380–1100 nm decreased with 0.45 percentage points. After immersion in hydrochloric acid solution for 80 h, the film hardness decreased to 8H, and the adhesion strength decreased to grade 1, while the transmittance increased with the increase of immersion time. When the immersion time reached 100 h, the film’s transmittance increased 0.81%.</p> Graphical Abstract <p></p>