cm9b02973_si_001.pdf (2.11 MB)
Tunable and Stable White Light Emission in Bi3+-Alloyed Cs2AgInCl6 Double Perovskite Nanocrystals
journal contribution
posted on 2019-12-12, 19:42 authored by Debjit Manna, Tapan Kumar Das, Aswani YellaLead-free double perovskite nanocrystals (NCs) of Cs2AgIn1–xBixCl6 (x = 0, 0.05, 0.15, 0.3, 0.6,
and 1) were synthesized with control over the size distribution. Detailed
structural studies were carried out on the resulting double perovskite
NCs to confirm the alloying and structural modification. Alloying
of Bi leads to change in optical properties, such as the band gap,
and enhancement in oscillator strength of first excitonic transition
and the white light emission (WLE) properties. The band gap of the
double perovskite NCs was estimated; a direct band gap transition
value of ∼3.46 eV is obtained for pure Cs2AgInCl6 NCs. This value of the band gap has reduced with increase
of Bi doping, which also leads a band gap transition from direct to
indirect band gap. This system exhibits a sub-band gap emission between
∼570 and 620 nm along with band-edge emission, which is strongly
dependent on the alloying concentration. A gamut of emission is observed
in the alloyed systems. The Commission International de I’Eclairage
(CIE) coordinates of (0.36, 0.35) for the 30% Bi-doped sample, with
color rendering index values of ∼91, and correlated color temperature
of 4443 with Duv of −0.0065 are
observed, which are found to be very promising for WLE applications.