Improvement of quality and stability of MAPbI3 films grown by post annealing under high pressure argon atmosphere

Abstract Organic-inorganic hybrid perovskite MAPbI 3 films with large grain size and excellent photoelectric properties are obtained by annealing the precursors at Ar atmosphere with pressure up to 10 MPa. In comparing to the film annealing at Ar with 0.1 MPa, 4 times lager grains are observed with the film annealing at the Ar atmosphere with the pressure of 6 MPa. The structural stability in respect to temperature is confirmed by the temperature dependence of x-ray diffraction. The band gap of MAPbI 3 films may be adjusted by varying the annealing pressure. There is one order of magnitude in intensity of photoluminescence (PL) due to annealing at the Ar atmosphere with high pressure, even the intensity of PL increases with increasing the temperature up to 35 °C. Post annealing with high atmosphere pressure may be a new method in fabricating high performance MAPbI 3 films.