Berlin 2015 – scientific programme
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AKE: Arbeitskreis Energie
AKE 8: Energy Storage I, Mobility, Materials
AKE 8.5: Talk
Tuesday, March 17, 2015, 12:00–12:15, A 151
Photoluminescence and hydrogen storage properties of gallium nitride hexagonal nano-sheets — •Ghulam Nabi1,2, Yong Lei1, and Abdul Majid2 — 1Institute of Physics & Institute of Micro- and Nanotechnologies (ZIK MacroNano), Technische Universität Ilmenau, 98693 Ilmenau, Germany — 2Department of Physics, University of Gujrat, Gujrat, Pakistan
A novel morphology of gallium nitride (GaN) hexagonal nano-sheets (HNSs) have been synthesized by chemical vapor deposition (CVD) method at 1200 °C. Photoluminescence (PL) and hydrogen storage capabilities of hexagonal nano-sheets (HNSs) at different temperatures have been investigated first time. Maximum hydrogen storage capacities of 1.45wt%, 1.71wt% and 2.12 wt% have shown an increasing trend of hydrogen absorption capacity with increasing temperature at a fixed pressure of 5MPa. During desorption process under ambient pressure, about 79%, 79% and 78% releasing of the stored hydrogen has been noted at 100 °C, 200 °C and 300 °C respectively. Highly reversible absorption/desorption results exhibited by GaN HNSs are encouraging and promising for hydrogen storage applications. The PL spectrum has exhibited strong near-band-edge emission at 367 nm (3.38 eV). Defects related broad yellow band emission at 553 nm (2.24 eV) has also been observed, which plays significant role in the hydrogen absorption. The effect of hydrogen absorption on PL properties of GaN HNSs has also been studied that showed H2 absorption has a passivation effect on the point defects or impurities.