Temperature Induced Anomalous Exciton Localization Dynamics of CH3NH3Pb(I1-xBrx)3 Perovskite Material: A Monte Carlo Simulation

Recent experiments proclaimed that organic-inorganic hybrid halide perovskites outperform due to its thermal stability, low cost, and high power conversion efficiency (PCE). To analyze the photoluminescence (PL) spectra, PL peak position, and full width at half maximum (FWHM)) of CH
3
NH
3
PbI
3
, CH
3
NH
3
PbBr
3
, and CH
3
NH
3
Pb(l
1-x
Br
x
)
3
materials, we have adopted a numerical model with the Monte Carlo simulation (MCS) of exciton hopping and relaxation mechanism over a temperature regime 10K to 300K where bromine (Br) contents are taken as 0.2 to 0.8 with 0.2 intervals. From the result, the blue-shift continuously occurs until the phase transition from orthorhombic to tetragonal phase, and then a small red-shift occurs. After the small red-shift, a gradual blue-shift occurs up to the temperature reaches at 300K for every PL spectra. These shifts are performance-degrading parameters for temperature-dependent applications. With the proper investigation, the quantity of red-shift decreases in CH
3
NH
3
Pb(l
1-x
Br
x
)
3
and occurs at a lower temperature with increasing bromine (Br) content respectively. This analysis suggests that mixed halide (bromine-iodine) perovskite at Br = 0.2 content is more stable than other combinations.