Perovskite-Cavity Complex: the Modulated Optical Characteristics of Organometallic Halide Perovskite CH3NH3PbIxCl3-x Doped in Length Tunable Optical Microcavities

When organometallic halide perovskite semiconductors with continuous transition band were placed into an optical microcavity, interaction/modulation effect between confined photonic mode supported by cavity and free charge carriers mode triggered in perovskite occurred. In this metal insulator metal (MIM) microcavity, given the broad absorption region of perovskite CH3NH3PbIxCl3-x, the cavity resonant energy can be selectively designed to modulate the photophysical characteristics of perovskite charge carriers at different levels. Another advantage of using perovskite is that its band filling effect (charge carrier's accumulation process) and relaxation process could last for few and hundreds picoseconds respectively, allowing us to accurately examine the time-resolved couple modulating effect by microcavities. Steady-state and transient absorption (TA) spectra were carried out to experimentally confirm the modulation effect of microcavity on optical characteristics of perovskite free charge carriers. It is found that created binate new states around cavity-perovskite resonance emerged at different perovskite levels are mutually independent. Interestingly, the band filling process of these new states is found not affected while their fluence-dependent relaxation process is accelerated by microcavities. The results in our work show that we can selectively manipulate the optical characteristics (absorption and charge carriers lifetimes) of perovskite by length tunable optical microcavities. Our efforts may propose an interesting modulating system and trigger potential optical application based on perovskite light complex.