  Metal halide perovskite quantum dots (PQDs) have emerged as promising
materials due to their exceptional photoluminescence (PL) properties. A wide
range of applications could benefit from adjustable luminescence properties,
while preserving the physical and chemical properties of the PQDs. Therefore,
post-synthesis engineering has gained attention recently, involving the use of
ion-exchange or external stimuli, such as extreme pressure, magnetic and
electric fields. Nevertheless, these methods typically suffer from spectrum
broadening, intensity quenching or yield multiple bands. Alternatively,
photonic antennas can modify the radiative decay channel of perovskites via the
Purcell effect, with the largest wavelength shift being 8 nm to date, at an
expense of 5-fold intensity loss. Here, we present an optical nanoantenna array
with polarization-controlled quasi-bound-states-in-the-continuum (q-BIC)
resonances, which can engineer and shift the photoluminescence wavelength over
a ~39 nm range and confers a 21-fold emission enhancement of FAPbI3 perovskite
QDs. The spectrum is engineered in a non-invasive manner via lithographically
defined antennas and the pump laser polarization at ambient conditions. Our
research provides a path towards advanced optoelectronic devices, such as
spectrally tailored quantum emitters and lasers.
