Over
the past two decades, intensive research efforts have been
devoted to suppressions of Auger recombination in metal-chalcogenide
and perovskite nanocrystals (PNCs) for the application of photovoltaics
and light emitting devices (LEDs). Here, we have explored dodecahedron
cesium lead bromide perovskite nanocrystals (DNCs), which show slower
Auger recombination time compared to hexahedron nanocrystals (HNCs).
We investigate many-body interactions that are manifested under high
excitation flux density in both NCs using ultrafast spectroscopic
pump–probe measurements. We demonstrate that the Auger recombination
rate due to multiexciton recombinations are lower in DNCs than in
HNCs. At low and intermediate excitation density, the majority of
carriers recombine through biexcitonic recombination. However, at
high excitation density (>1018cm–3)
a higher number of many-body Auger process dominates over biexcitonic
recombination. Compared to HNCs, high PLQY and slower Auger recombinations
in DNCs are likely to be significant for the fabrication of highly
efficient perovskite-based photonics and LEDs.