In photoluminescence experiments of hole-doped ${\mathrm{WSe}}_2$ monolayer, a counterintuitive phenomenon is observed: the emission from the lower-energy dark positive trion (${\mathrm{D}}^{+}$) anomalously diminishes at high hole densities, while the signal from the higher-energy bright positive trion (${\mathrm{X}}^{+}$) becomes dominant. In this work, we propose a nonradiative Auger recombination as the mechanism responsible for this paradoxical observation. We performed first-principles calculations based on density functional theory (DFT) to obtain the electronic band structure and Bloch wave functions of ${\mathrm{WSe}}_2$ monolayer. To accurately capture the many-body correlation within the trion complex, we utilized the stochastic variational method (SVM). Using this combined framework, we have quantified the density-dependent Auger recombination rates by applying Fermi's golden rule. Our theoretical analysis reveals that as the hole density increases, the Auger recombination rate for dark trions increases dramatically. Specifically, at a critical hole density of a few times ${10}^{12}{\mathrm{cm}}^{-2}$, our calculations show that the Auger lifetime drops below the nanosecond-scale measured lifetime of the dark positive trion at residual hole density. This nonradiative Auger process becomes the dominant pathway, effectively quenching the emission from $D^{+}$, and leading to the experimentally observed dominance of bright trions. This study provides a comprehensive theoretical framework for understanding the nonradiative interaction that governs trion dynamics in hole-doped ${\mathrm{WSe}}_2$ monolayer.

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• Trions
• Monolayer films
• Transition metal dichalcogenides
• Density functional calculations
• Photoluminescence