Halide perovskite solar cells (PSCs) offer high efficiency at low production costs, making them a promising solution for future photovoltaic technologies. Optimizing charge transport layers is crucial, with porous TiO2 widely used as electron transport layers (ETLs) due to their suitable energy band alignment, transparency, and abundance. However, their performance depends strongly on crystallinity, requiring high-temperature processing (>450 degrees C), which increases costs and limits their applicability on flexible substrates. Low-temperature wet-chemical methods face scalability issues due to material waste and hazardous solvents. Therefore, plasma-based technologies provide a scalable, eco-friendly alternative for fabricating oxide-based ETLs. This study presents a plasma-based synthesis of TiO2 layers using remote plasma-assisted vacuum deposition (RPAVD) and soft plasma etching (SPE) at temperatures below 200 degrees C, enabling precise control over microstructure and porosity. The resulting nanocolumnar and aerogel-like TiO2 films are antireflective and enhance optical and electronic properties, leading to improved PSC efficiency (champion PCE = 14.6%) comparable to high-temperature processed devices. The devices are based on a 3D organometal perovskite with mixed cations (MA, FA, Cs, Rb) and halides (I, Br), with a nominal composition of (Rb(0.03)Cs(0.03)FA(0.69)MA(0.25))(PbI3)(0.83)(PbBr3)(0.17). Our results highlight the potential of RPAVD+SPE for producing low-temperature ETLs, offering a feasible, industrially scalable solution for flexible, high-performance photovoltaics.