Purcell Enhancement and Wavelength Shift of Emitted Light by CsPbI3 Perovskite Nanocrystals Coupled to Hyperbolic Metamaterials.

Hamid Pashaei Adl,Sergio I Molina,Vladimir S Chirvony,Setatira Gorji,María De La Mata,Carlos J Zapata-Rodríguez,Luisa M Valencia,Isaac Suárez,Jesús Hernández-Saz,Juan P Martínez-Pastor,Iván Mora-Seró,Andrés F Gualdrón-Reyes,Mojtaba Karimi Habil

doi:10.1021/acsphotonics.0c01219

Abstract

Manipulation of the exciton emission rate in nanocrystals of lead halide perovskites (LHPs) was demonstrated by means of coupling of excitons with a hyperbolic metamaterial (HMM) consisting of alternating thin metal (Ag) and dielectric (LiF) layers. Such a coupling is found to induce an increase of the exciton radiative recombination rate by more than a factor of three due to the Purcell effect when the distance between the quantum emitter and HMM is nominally as small as 10 nm, which coincides well with the results of our theoretical analysis. Besides, an effect of the coupling-induced long wavelength shift of the exciton emission spectrum is detected and modeled. These results can be of interest for quantum information applications of single emitters on the basis of perovskite nanocrystals with high photon emission rates.

Highlights

Manipulation of the exciton emission rate in nanocrystals of lead halide perovskites (LHPs) was demonstrated by means of coupling of excitons with a hyperbolic metamaterial (HMM) consisting of alternating thin metal (Ag) and dielectric (LiF) layers
Nanofabrication techniques have enabled the development of different optical metamaterials, which are designed to achieve and exploit light−matter interaction unattainable with natural materials.[1−4] Among the varieties of metamaterials proposed and fabricated so far, hyperbolic metamaterials (HMMs)[5−8] have rapidly gained a key role in nanophotonics due to their peculiar ability to manipulate the near field of a quantum emitter (QE).[9−11] The most intriguing feature of these anisotropic HMM structures is the increase of the photon density of states, which can be used to engineer the light−matter interaction, with emitters, by increasing their emission rates when they are placed close to the HMM surface
Two HMM structures were grown with different nominal period and thicknesses of metal and dielectric layers and real thicknesses were estimated at the center of the wafer by HAADF-STEM

Summary

■ RESULTS AND DISCUSSION

The radiative exciton lifetime of 1.5 ns extracted from the reference sample is very close to the values measured in freshly prepared samples on glass substrates and values reported by us and other authors elsewhere.[59,66] As aforementioned, a clear shortening of the exciton radiative recombination time from 1.5 to 0.5 ns was obtained in average, meaning a clear Purcell enhancement around 3 for the thinnest spacer in the HMMspacer-PNC structure For a very thick spacer (the case of our reference device), the point dipole is very far from the multilayer, and its interaction with the metal-dielectric multilayer is substantially reduced, and a great amount of the dipole power emits to the top side of the HMM structure

■ CONCLUSION

■ ACKNOWLEDGMENTS

■ REFERENCES