Fig.4

Analysis of biexciton lifetime from CsPbBr₃ nanocrystals. a Size dependence of biexciton radiative lifetime, defined as one quarter of single exciton lifetime [53], and its fitting (blue line) by\({\tau }_{X}={\tau }_{X0}+a{V}^{\alpha }\). The fitting parameters take \({\tau }_{X0}=4000\) ps, \(a=55\), and\(\mathrm{\alpha }=0.68\). b Size dependence of biexciton Auger lifetime and its fitting (red line) by\({\tau }_{\text{Auger}}=b{V}^{\beta }{e}^{{\left(\frac{V}{{V}_{0}}\right)}^{\gamma }}\). The fitting parameters take \(b=0.05\) and \({V}_{0}=450\) nm³ under the theoretical values of \(\beta =1\) (from reference [14]) and\(\gamma =\frac{2}{3}\). c Size dependence of biexciton lifetime and its fitting (black line) by \({\uptau }_{XX}=\frac{{\uptau }_{r,XX}\times {\uptau }_{\text{Auger}}}{{\uptau }_{r,XX}+{\uptau }_{\text{Auger}}}\)