In excitonic solar cells, where the primary photoexcitation is a bound exciton, a hetorojunction is needed to provide enough driving force to generate free charges. Unfortunately, this results in intrinsic energetic losses, which although conceivably surmountable have lead to relatively slow progress in efficiency over the last decade. Noteworthy, in the last year, the scientific community involved in the development of ”emerging” solar cells have realised a succession of breakthroughs employing ionic crystalline assemblies assuming a perovskite structure. Perovskites have been reported replacing the dye in dye-sensitize solar cells (DSC) with liquid-electrolyte based (power conversion efficiency, h= 6.5%) and solid state cells with spiro-OMeTAD and conjugated polymers as the solid-state hole conductor (h over 9 %) , or as hole-conductors (h = 8.5%). These devices have generally shown impressive photocurrent generation, while the photovoltages achieved still indicated some significant losses. One particular device concept, where the mesoporous TiO₂-perovskite heterojunction is removed, eludes this trend: the “meso-superstructured solar cell” that sees an organometal mix-halide perovskite, CH₃NH₃PbI_3-xCl_x, employed as light harvesting and electron transporting layer and a spiro-OMETAD as hole transporter. A mesoporous Al₂O₃ layer is employed as insulating “scaffold” upon which the perovskite is deposited. The device exhibits exceptionally high open-circuit photovoltages of over 1.1 volts, despite the relatively narrow absorber band gap, which lead to a record hof10.9% under standard conditions. As the operation of these cells is quite different to the standard DSC device, a number of questions need to be answered. Here we will examine the effect of Chlorine doping on the optoelectronic properties of the CH₃NH₃PbI₃ compound, with a particular focus on the functionalities of the principal interfaces in the device. The nature of the primary photo-excitation will be unveiled. It will be shown that the primary photoexcitation at low temperature is excitonic. However, the exciton is predominantly ionized at room temperature, leading to spontaneous free charge generation establishing the non-excitonic solar cell operation.The diffusion lengths of the photoexcitation are found  >1 micrometer in the mixed halide perovskite, an order of magnitude greater than the absorption depth. By contrast, the triiodide absorber has electron-hole diffusion lengths of ~100 nanometers. These results justify the high efficiency of planar heterojunction perovskite solar cells, and identify a critical parameter to optimize for future perovskite absorber development.