Investigation of Perovskite Solar Cells Using Guanidinium Doped MAPbI₃ Active Layer

In this work, guanidinium (GA⁺) was doped into methylammonium lead triiodide (MAPbI₃) perovskite film to fabricate perovskite solar cells (PSCs). To determine the optimal formulation of the resulting guanidinium-doped MAPbI₃ ((GA)_x(MA)_1−xPbI₃) for the perovskite active layer in PSCs, the perovskite films with various GA⁺ doping concentrations, annealing temperatures, and thicknesses were systematically modulated and studied. The experimental results demonstrated a 400-nm-thick (GA)_x(MA)_1−xPbI₃ film, with 5% GA⁺ doping and annealed at 90 °C for 20 min, provided optimal surface morphology and crystallinity. The PSCs configured with the optimal (GA)_x(MA)_1−xPbI₃ perovskite active layer exhibited an open-circuit voltage of 0.891 V, a short-circuit current density of 24.21 mA/cm², a fill factor of 73.1%, and a power conversion efficiency of 15.78%, respectively. Furthermore, the stability of PSCs featuring this optimized (GA)_x(MA)_1−xPbI₃ perovskite active layer was significantly enhanced.