Study on photovoltaic stability and performance by incorporating tetrabutyl phosphonium iodide into the active layer of a perovskite type photovoltaic cell

A simple synthesis of an ionic liquid is carried out using a trialkylphosphine and an alkyl halide. The results showed that the quality of perovskite crystals is enhanced by the incorporation of B4PI, when the percentage is 1.5% the PCE of champion PSCs MA(98.5)(B4PI)(1.5)PbI(3)increases significantly from 15.5%, with aV(OC)of 0.957 mV,J(SC)of 23.6 mA cm(-2), and an FF of 68.4%. Stability tests show that excess B4PI by 20% has a protective effect against humidity, MA(80)(B4PI)(20)PbI(3)was more stable towards humidity, losing only 20% efficiency for 200 h.