Tuning exciton recombination rates in doped transition metaldichalcogenides

TL;DR

This paper explores how doping influences exciton recombination in monolayer transition metal dichalcogenides, revealing that high doping levels increase the exciton-exciton annihilation threshold and affect photoluminescence efficiency.

Contribution

It provides new insights into the relationship between doping, recombination pathways, and exciton dynamics in TMDs, aiding future device design.

Findings

Higher doping raises the EEA threshold.

Doped TMDs show dominant trion recombination.

Doping modifies photoluminescence quantum yield.

Abstract

Monolayer transition metal dichalcogenides (TMDs) are direct gap semiconductors that hold great promise for advanced applications in photonics and optoelectronics. Understanding the interplay between their radiative and non-radiative recombination pathways is thus of crucial importance not only for fundamental studies but also for the design of future nanoscale on-chip devices. Here, we investigate the interplay between doping and exciton-exciton annihilation (EEA) and their impact on the photoluminescence quantum yield in different TMD samples and related heterostructures. We demonstrate that the EEA threshold increases in highly doped samples, where the radiative and non-radiative recombination of trions dominates.