title: Strong infrared photoluminescence in highly porous layers of large faceted Si crystalline nanoparticles.
abstract: Almost all physical processes in solids are influenced by phonons, but their effect is frequently overlooked. In this paper, we investigate the photoluminescence of large silicon nanoparticles (approximately 100 nm size, synthesized by chemical vapor deposition) in the visible to the infrared detection range. We find that upon increasing laser irradiance, an enormous photoluminescence emission band appears in the infrared. Its intensity exhibits a superlinear power dependence, increasing over four orders of magnitude in the investigated pump power range. Particles of different sizes as well as different shapes in porous layers are investigated. The results are discussed taking into account the efficient generation of phonons under high-power pumping, and the reduced capability, porosity dependent, of the silicon nanoparticles to exchange energy with each other and with the substrate. Our findings are relevant for heat management strategies in silicon.
authors.affiliation: Van der Waals - Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: E M L D
authors.initials: EM
authors.lastname: de Jong
authors.affiliation: IMM - Consiglio Nazionale delle Ricerche (CNR-IMM), VIII Strada n°5 Zona Industriale, 95121 Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Mannino
authors.affiliation: IMM - Consiglio Nazionale delle Ricerche (CNR-IMM), VIII Strada n°5 Zona Industriale, 95121 Catania, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Alberti
authors.affiliation: IMM - Consiglio Nazionale delle Ricerche (CNR-IMM), VIII Strada n°5 Zona Industriale, 95121 Catania, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Ruggeri
authors.affiliation: IMM - Consiglio Nazionale delle Ricerche (CNR-IMM), VIII Strada n°5 Zona Industriale, 95121 Catania, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Italia
authors.affiliation: ESRF, the European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
authors.forename: F
authors.initials: F
authors.lastname: Zontone
authors.affiliation: ESRF, the European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Chushkin
authors.affiliation: Dipartimento di Fisica e Astronomia, Università di Catania, Via Santa Sofia 64, 95123 Catania, Italy.
authors.forename: A R
authors.initials: AR
authors.lastname: Pennisi
authors.affiliation: Van der Waals - Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Gregorkiewicz
authors.affiliation: Dipartimento di Fisica e Astronomia, Università di Catania, Via Santa Sofia 64, 95123 Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Faraci