1. The Narrow Energy Gap Dilute Nitride Alloy In(AsN) A. Patanè, O. Makarovsky, W.H.M. Feu, L. Eaves School of Physics and Astronomy The University of Nottingham, UK Collaborators A. Krier and Q. Zhuang Physics Department, Un. of Lancaster, UK R. Airey EPSRC Facility for III-Vs, Un. of Sheffield, UK O. Dravchenko and M. Helm Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, Germany EU High Magnetic Field Labs, http://www.ru.nl/hfml http://www.nottingham.ac.uk/~ppzphy17/

2. “Trends in the electronic structure of dilute nitride alloys” E.P. O’Reilly et al., SST 24 033001 (2009) The band structure of III-V-Ns is determined by the distribution of energy levels due to N-impurities and N-clusters and their hybridization with the extended CB states. GaAsN InPN InAsN N-level CBE 0.2 eV 0.4 eV E = 1 eV N-pairs and clusters Comparing III-N-Vs

3. “Theory of the electronic structure…” A. Zunger et al., PRB 64 115208 (2001) Electron localization occurs if the CBE of the dilute ‘‘impurity’’ species lies below that of the host III-V, and the impurity electron mass, m e, is heavy. GaN GaAs InN InAs 0.3 eV m e m e =0.13m o 0.02m o N CBE GaAsNInAsN GaAsN InAsN Electron mass Comparing III-N-Vs

4. This work Tuning the band gap Tuning the band gap Electron mobility and cyclotron mass Electron mobility and cyclotron mass Electron coherence length Electron coherence length Hot electron dynamics Hot electron dynamics Probing electronic properties

5. De la Mare et al., APL 95, 031110 ‘09 Admixing of the N-levels with the band states of the III-V shifts the PL emission to longer >3m  A large relative change of the band gap energy, E g : -E g /E g >10% at x=1% Prospects for IR gas sensing, security applications, lasers… InAsN for IR-Optoelectronics InAs 1-x N x on GaAs grown by MBE Kudrawiec et al. APL 94, 151902 ’09 J. Misiewicz (Wroclaw Un., Poland)

6. De la Mare et al., APL 95, 031110 ‘09 Admixing of the N-levels with the band states of the III-V shifts the PL emission to longer >3m  A large relative change of the band gap energy, E g : -E g /E g >10% at x=1% Prospects for IR gas sensing, security applications, lasers… InAsN for IR-Optoelectronics x=1% InAs 1-x N x on GaAs grown by MBE TEM, R. Beanland (UK)

7. Hall Mobility InAsN Patanè et al. APL 93 252106 ’08 Nitrogen reduces the electron mobility. GaAsN  is limited by electron scattering by N-atoms, -pairs and–clusters. These effects are stronger in GaAsN than in InAsN due to the vicinity of the N-related states to the CBE. Model for GaAsN predicts a strong reduction of the mobility and electron mean free path due to the N-levels. Fahy et al. PRB 74, 035203 ‘06 GaAsN

8. Electron Cyclotron Mass x=0% 0.4% 1.0% 0.6% T =100 K = 2.9THz The cyclotron mass increases with increasing x. Comparing the N-induced change of the mass in InAsN and GaAsN. Patanè et al. PRB 80 115207 ’09 (m e ) GaAsN LCINS, O’Reilly CR InAsN CR/PR GaAsN InAs 1-x N x