Decorating wide band gap CH₃NH₃PbBr₃ perovskite with 4AMP for highly efficient and enhanced open circuit voltage perovskite solar cells

Halides based organic-inorganic solar cells have attracted huge attention for efficient energy harvesters owing to their low fabrication cost, large functioning area, long lifetime, and high conversion efficiency. Here we report the fabrication of pristine and aminomethyl piperidinium (4AMP) doped CH₃NH₃PbBr₃ based thin film using spin coating technique to explore its potential for energy harvesting. The structural analysis confirmed the development of the rhombohedral structure of pristine and doped CH₃NH₃PbBr₃. SEM and AFM images revealed that grains for the pure sample are highly compact linked with each other with sharp grain boundaries but their size increased when doped with 4AMP. A direct bandgap of 2.341 eV is noticed for pristine which is slightly decreased to 2.311 eV as a result of doping. The calculation of space charge limited current, PL decay profile analysis, charge transfer resistance, and Mott Schottky analysis provide quite convincing evidence regarding the high conversion efficiency of these films. A sufficiently high value of short circuit current density resulted in high efficiency of pristine MAPbBr₃ i.e., 8.46% which increased to 10.21% due to improvement of solar cells parameters such as V_oc of 1.46 V when doped with 4AMP. These values of efficiencies make the halide based organic compositions viable for solar cell applications.