[en] Highlights: • Template free large area uniform 1-directional TiO₂. • Highly uniform Nano-forests like TiO₂ structures. • Facile charge collection and lower losses due to 1-D TiO₂ structures. • Triple cation based perovskite in conjugation with these 1-D TiO₂ structures allowed highly efficient and stable perovskite solar cells fabrication. During the last years, perovskite solar cells have gained increasing interest among the photovoltaic community, in particularly after reaching performances at par with mature thin film based PV. This rapid evolution has been fostered by the compositional engineering of perovskite and new device architectures. In the present work, we report the fabrication of perovskite solar cells based on highly ordered 1-dimensional vertically oriented TiO₂ nano-forests. These vertically oriented porous TiO₂ photoanodes were deposited by physical vapor deposition in an oblique angle configuration, a method which is scalable to fabricate large area devices. Mixed (MA_0.15FA_0.85)Pb(I_0.85Br_0.15)₃ or triple cation Cs_0.05(MA_0.15FA_0.85)_0.95Pb(I_0.85Br_0.15)₃ based perovskites were then infiltrated into these 1-dimensional nanostructures and power conversion efficiencies of 16.8% along with improved stability was obtained. The devices fabricated using 1D-TiO₂ were found to be more stable compare to the classical 3-dimensional TiO₂ photoanodes prepared by wet chemistry. These 1-D photoanodes will be of interest for scaling up the technology and in other opto-electrical devices as they can be easily fabricated utilizing industrially adapted methodologies.