biostudies-literaturePasquale GSwiss National Science FoundationDeutsche ForschungsgemeinschaftMinistry of Education, Culture, Sports, Science and TechnologyH2020 Future and Emerging TechnologiesJapan Society for the Promotion of Science8883-8891https://www.ebi.ac.uk/biostudies/studies/S-EPMC9707521biostudies-literatureUnknown22(22)Interactions among a collection of particles generate many-body effects in solids that result in striking modifications of material properties. The heavy carrier mass that yields strong interactions and gate control of carrier density over a wide range makes two-dimensional semiconductors an exciting playground to explore many-body physics. The family of III-VI metal monochalcogenides emerges as a new platform for this purpose because of its excellent optical properties and the flat valence band dispersion. In this work, we present a complete study of charge-tunable excitons in few-layer InSe by photoluminescence spectroscopy. From the optical spectra, we establish that free excitons in InSe are more likely to be captured by ionized donors leading to the formation of bound exciton complexeNano lettersFlat-Band-Induced Many-Body Interactions and Exciton Complexes in a Layered Semiconductor.PMC9707521881603175822JP20H00354JPMXP0112101001177007CRC 1083JP19H05790164015785219Pasquale GKis ACernevics KNTagarelli FWatanabe KYazyev OVTaniguchi TPerea-Causin RSun ZMalic EfalseFlat-Band-Induced Many-Body Interactions and Exciton Complexes in a Layered Semiconductor.Interactions among a collection of particles generate many-body effects in solids that result in striking modifications of material properties. The heavy carrier mass that yields strong interactions and gate control of carrier density over a wide range makes two-dimensional semiconductors an exciting playground to explore many-body physics. The family of III-VI metal monochalcogenides emerges as a new platform for this purpose because of its excellent optical properties and the flat valence band dispersion. In this work, we present a complete study of charge-tunable excitons in few-layer InSe by photoluminescence spectroscopy. From the optical spectra, we establish that free excitons in InSe are more likely to be captured by ionized donors leading to the formation of bound exciton complexe2022-01-01T00:00:00Z2022 Nov2025-04-04T13:10:12.669Z2025-04-04T13:10:12.669ZS-EPMC97075213634687410.1021/acs.nanolett.2c02965