title: Carrier trapping and confinement in Ge nanocrystals surrounded by Ge3N4.
abstract: We investigated the optical properties of Ge nanocrystals surrounded by Ge3N4. The broad emission ranging from infrared to blue is due to the dependence on the crystal size and preparation methods. Here, we report high resolution Photoluminescence (PL) attributed to emission from individual Ge nanocrystals (nc-Ge) spatially resolved using micro-photoluminescence and detailed using temperature and power-dependent photoluminescence studies. The measured peaks are shown to behave with excitonic characteristics and we argue that the spread of the nc-Ge peaks in the PL spectrum is due to different confinement energies arising from the variation in size of the nanocrystals.
authors.affiliation: School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea.
authors.forename: Youngsin
authors.initials: Y
authors.lastname: Park
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK.
authors.forename: Christopher C S
authors.initials: CC
authors.lastname: Chan
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK.
authors.forename: Benjamin P L
authors.initials: BP
authors.lastname: Reid
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK.
authors.forename: Luke
authors.initials: L
authors.lastname: Nuttall
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Taylor
authors.affiliation: National Institute of Nanomaterials Technology (NINT), Pohang University of Science and Technology, Pohang 37673, Korea.
authors.forename: Nam-Suk
authors.initials: NS
authors.lastname: Lee
authors.affiliation: Beamline Division, Pohang Accelerator Laboratory, Pohang 37673, Korea.
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Lee