The organo-inorganic perovskites are extraordinary materials that have recently revolutionized the field of photovoltaics due to their low-cost fabrication and high optical absorption. In a short period, they reached great efficiency. Many parameters which affect the quality of perovskite films can be optimized, so the efficiency of these devices can be further improved. In perovskite solar cells, the perovskite layer is an active layer that absorbs the visible part of the spectrum, resulting in the formation of the electron-hole pair. To decrease the recombination of charge carriers, the construction of solar cells requires the existence of two additional layers in order to separate the holes and electrons. TiO2 could be used as an electron transport layer because its conduction band (CB) lies under the CB of perovskite. In that way, electrons diffuse from CB of perovskite to CB of TiO2. For these experiments, TiO2 nanotubular structure provides a one-dimensional transmission channel for the charge carriers, which resulting in faster carrier transport. Perovskite methylammonium lead bromide (MAPbBr3) was coupled with TiO2 nanotube arrays which were synthesized by anodization of Ti foil and annealed at 450 °C. The most used methods for deposition of perovskite materials on mesoporous and planar TiO2 are: one-step deposition, two-step sequential deposition, and vapor-assisted solution processing. Disadvantage of these methods is a small contact area between TiO2 and perovskite. The aim of this research was to increase the contact surface of the perovskite and TiO2 nanotubes by filling the nanotubes with the perovskite material in order to improve electron transport
