Impact of PTQ11 polymer doping on the optoelectronic and structural properties of a CH3NH3PbI3 perovskite photovoltaic cell

•High-quality tetragonal MAPbI3 films are fabricated using PTQ11 polymer.•The (220)-oriented MAPbI3 films exhibit large crystal grains of 1.63 µm.•The large crystal grains lead to reduced trap density and improved charge transfer.•A record efficiency of 18.24 % is achieved for the PTQ11-9 mg/mL-based solar cell. At present, one of the most swiftly progressing domains in solar photovoltaics is perovskite-based solar cells. Chemical modification of perovskites with foreign atoms represents a potentially fruitful approach to customizing material characteristics with the aim of enhancing the functionality and durability of solar cells. In this study, we first documented the inverted structure of PTQ11 polymer-doped perovskite solar cells composed of CH3NH3PbI3 (MAPbI3) perovskite thin film. The findings indicate that the active layer morphology is enhanced through PTQ11 doping, leading to rapid suppression of photoluminescence and delayed carrier recombination. The XRD and Raman spectral analyses revealed the crystalline, single phase, tetragonal, and highly pure MAPbI3 thin film with the preferred (220) orientation. Energy gaps ranging from 1.596 eV to 1.577 eV and absorption coefficients exceeding 105 cm−1 were characteristics of the doped thin film, which varied with the doping concentration. A transition occurred on the perovskite film’s surface to form smooth, compressed pores measuring 1.63 µm in diameter. This modification potentially enhanced the photovoltaic performance by facilitating charge transport. With an open circuit voltage of 1.11 V, a power conversion efficiency (PCE) of 18.24 %, a short-circuit current density of 22.32 mA/cm2, and a fill factor of 73.65 %, the PTQ11-9 mg/mL sample constituted the solar cell device base. Hence, the findings suggest that the doping of PTQ11 polymer represents a potentially effective approach to improve the performance of perovskite solar cells.