Wafer-scale growth of two-dimensional semiconductors remains a key challenge for their integration into photonic technologies. While most studies of two-dimensional semiconductors have focused on transition metal dichalcogenides and their scalable fabrication, comparatively little attention has been given to III-VI monochalcogenides. Here, we report wafer-scale growth of gallium selenide (GaSe) by metal-organic chemical vapor deposition (MOCVD) and investigate its structural and optical properties for visible-range classical and quantum light emission. Two samples with thicknesses ranging from a few monolayers to several micrometers, controlled via the growth time, were investigated. The 30-minute grown sample yields intense, broad photoluminescence spanning 1.7--2.0eV, whereas the thinner 3-minute sample exhibits discrete narrow emission lines and single-photon emission with (g(2)(0)=0.15±0.10). Remarkably, cathodoluminescence mapping reveals pronounced spatial localization of both spectrally narrow and broad emission centers. Together with temperature-dependent power-law analysis and Raman mapping, our results indicate defect-induced emission rather than intrinsic excitonic recombination. These findings establish wafer-scale MOCVD grown 2D GaSe as a platform for classical and non-classical light sources and highlight defect-engineered localization as a route toward scalable quantum photonics.
@article{arxiv.2605.23418,
title = {Localized Excitonic Emission in Wafer-Scale MOCVD-Grown GaSe 2D Nanosheets for Classical and Non-Classical Light Sources},
author = {Bhabani Sankar Sahoo and Nils Fritjof Langlotz and Shachi Machchhar and Kartik Gaur and Robin Günkel and Max Bergmann and Naghmeh Ghadghooni and Aris Koulas-Simos and Jürgen Belz and Chirag Chandrakant Palekar and Maximilian Ries and Kerstin Volz and Stephan Reitzenstein and Imad Limame},
journal= {arXiv preprint arXiv:2605.23418},
year = {2026}
}