Increasing power consumption and need for the green, renewable and cost-efficient energy source draw lot of attention to metal halide perovskites in past two decades. Metal halide perovskites have shown exceptional potential in converting solar energy to electric power in photovoltaics with very high efficiency, they are composed of earth abundant materials and the production cost is very low, yet their application is hampered by limited operational stability. This stimulated the development of hybrid layered (two-dimensional, 2D) halide perovskites based on hydrophobic organic spacers, templating perovskite slabs. Incorporation of the small organic spacers into the perovskite layers leads to larger stability and disfavours transition into the non-photoactive phase. However, conventional organic spacer cations are electronically insulating, resulting in charge confinement within the inorganic slabs, thus limiting their functionality. This can be ameliorated by extending the π-conjugation of the spacer cations. We demonstrate the capacity to access Ruddlesden-Popper and Dion-Jacobson 2D perovskites incorporating for the first time aryl-acetylene-based (4-ethynylphenyl)‍methylammonium (BMAA) and buta-1,3-diyne-1,4-diylbis‍(4,1-phenylene)‍dimethylammonium (BDAA) spacers, respectively. We assess their unique opto‍(electro)‍ionic characteristics by a combination of techniques and apply them in mixed-dimensional perovskite solar cells that show superior device performances with a power conversion efficiency of up to 23% and higher operational stability, opening the way for multifunctionality in layered hybrid materials and their application. At the interface between perovskite active layer and charge transport layers, the aryl-acetylene-based spacers serve not only as passivating layer, but they are also actively involved in the charge extraction from the perovskite to the hole transport material. We show two different mechanisms of the charge extraction for the studied organic spacers and explain the enhanced power conversion efficiency compared to the untreated pure 3D perovskite. Moreover, theoretical analysis suggests that the BDAA spacer presents a very promising system for interfacial modulation and active charge transport with both electron and hole transport layers. Efficient charge transport properties are enabled by favourable band alignment of the BDAA spacer with the perovskite absorber and by the extended π-conjugated aryl-acetylene core. The π orbitals delocalised through the entire system could effectively overlap with both perovskite and charge-transport layers, offering a new approach to designing multifunctional materials and interfaces.