It is established that fossil fuels enabled a huge global economic growth although resulted to a fragile equilibrium between fuel prices and economic development, an unsustainable exploitation of the natural resources and prompted the ongoing environmental and societal crisis. Solar-driven energy production is pivotal for glass-architecture buildings, public transportation, domestic/corporate roof-tops/windows and rural areas (i.e. greenhouses); oriented to EU policies for Decarbonization of the EU building stock and European Green Deal for efficient, clean and cheap energy. In the last decade, solution-processable metal halide perovskite solar cells (PSCs), a technology originated from dye-sensitized solar cells (DSSCs), the most prominent alternative to the dominant (95% market stake) 1st gen. PVs, has emerged. Major drawbacks towards the commercialization of PSCs are the: i) instability in prolonged environmental exposure (moisture, oxygen, irradiation), ii) toxicity of employed lead and its derivatives (i.e. PbI2) and iii) crystal defects resulting in energy losses due to non-radiative charge recombination. HaloCell aims to hamper losses due to non-radiative recombination, embody protection towards environmentally driven-hydrolysis/oxidation and manage toxicity of PSCs and luminescent solar concentrators (LSCs), harnessing a holistic halogen bonding strategy. Multifunctional tailored organic compounds will be utilized to enable selective interplay with perovskite crystal lattice via halogen bonding interactions towards PSCs with power conversion efficiencies and long-term stability under stress conditions (illumination, high temperature, ambient air) exceeding current state-of-the-art. The newly-developed PSCs will be exploited as solar cells coupled to luminescent solar concentrators for the fabrication of smart architecture elements (plexiglass windows).