Highly Efficient Exciton Modulation in MoSe$_2$/PdSe$_2$ Heterostructures

Petr Rozhin; Emma Contin; Danae Katrisioti; Till Weickhardt; Muhammad Sufyan Ramzan; Micol Bertolotti; Nouha Loudhaief; Bing Wu; Zdeněk Sofer; Takashi Taniguchi; Kenji Watanabe; Leonardo Puppulin; Stefano Dal Conte; Caterina Cocchi; Ioannis Paradisanos; Giancarlo Soavi; Giovanni Antonio Salvatore; Domenico De Fazio

arXiv · 2605.13211

Highly Efficient Exciton Modulation in MoSe$_2$/PdSe$_2$ Heterostructures

Petr Rozhin·Emma Contin·Danae Katrisioti·Till Weickhardt·Muhammad Sufyan Ramzan·Micol Bertolotti·Nouha Loudhaief·Bing Wu·Zdeněk Sofer·Takashi Taniguchi·Kenji Watanabe·Leonardo Puppulin·Stefano Dal Conte·Caterina Cocchi·Ioannis Paradisanos·Giancarlo Soavi·Giovanni Antonio Salvatore·Domenico De Fazio

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Abstract

Controlling exciton recombination in atomically thin semiconductors is central to their optoelectronic functionality, as the competition between radiative and non-radiative decay channels governs emission efficiency. Existing approaches, such as defect passivation, chemical doping, dielectric engineering, and strain tuning, primarily aim to suppress non-radiative losses. Here, we report a pronounced $\sim$6-fold enhancement of room-temperature A-exciton emission in a type-I MoSe$_2$/PdSe$_2$ van der Waals heterostructure, yielding a photoluminescence quantum yield of 6 %, compared to $\sim$1 % for as-exfoliated monolayer MoSe$_2$. This enhancement is accompanied by strong quenching of the B-exciton, consistent with interlayer electronic coupling that redistributes exciton populations toward the radiative A-exciton channel. Power- and temperature-dependent measurements reveal a suppression of exciton-exciton annihilation and a crossover to quenched emission at low temperature, indicating a redistribution of exciton relaxation pathways. Photoluminescence excitation spectroscopy further reveals a broadband enhancement spanning 450-725 nm, ruling out a resonance-specific mechanism. These results demonstrate that interlayer electronic coupling can be used as an efficient means to redirect exciton populations toward radiative channels, enhancing emission efficiency in two-dimensional semiconductors without chemical modification or strain.

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Petr Rozhin, Emma Contin, Danae Katrisioti, Till Weickhardt, Muhammad Sufyan Ramzan, Micol Bertolotti, Nouha Loudhaief, Bing Wu, Zdeněk Sofer, Takashi Taniguchi, Kenji Watanabe, Leonardo Puppulin, Stefano Dal Conte, Caterina Cocchi, Ioannis Paradisanos, Giancarlo Soavi, Giovanni Antonio Salvatore, Domenico De Fazio. 2026-05-18. Highly Efficient Exciton Modulation in MoSe$_2$/PdSe$_2$ Heterostructures. https://arxiv.org/abs/2605.13211

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