Exploring plasmons weakly coupling to perovskite excitons with tunable emission by energy transfer

Localized surface plasmon resonance (LSPR) has caused extensive concern and achieved widespread applications in optoelectronics. However, the weak coupling of plasmons and excitons in a nanometal/semiconductor system remains to be investigated via energy transfer. Herein, bandgap tunable perovskite films were synthesized to adjust the emission peaks, for further coupling with stable localized surface plasmons from gold nanoparticles. The degree of mismatch, using steady-state and transient photoluminescence (PL), was investigated systematically in two different cases of gold nanoparticles that were in direct contacting and insulated. The results demonstrated the process of tuning emission coupled to LSPR via wavelength-dependent photoluminescence intensity in the samples with an insulating spacer. In the direct contact case, the decreased radiative decay rate involves rapid plasmon resonance energy transfer to the perovskite semiconductor and non-radiative energy transfer to metal nanoparticles in the near-field range.