| Abstract [eng] |
Perovskites are materials with very unique properties which can be applied to many different fields. They have enormous potential in optoelectronics and could be used competitively for LED and solar cell manufacturing if their stability problems were to be solved. This thesis presents investigation of ion migration in perovskite films addressed by means of the optical and EFISHG technique, as well as analysis of the influence of ion redistribution on dynamic performance of perovskite light emitting diode (PeLED). The time-resolved EFISHG investigations were performed by using wide field optical microscope. Furthermore, MAPbI3 perovskite LEDs were investigated by pulsed electrical pumping which enabled to study the influence of external factors: positive and negative voltage and light soaking. Analysis of the results suggests that the complex operation dynamics on time scales from subseconds to minutes and hours is caused by redistribution of single type mobile species, most likely iodine ions, changing the carrier injection, spatial electric field and carrier density distributions and density of nonradiative recombination centres. |
