Dual-wavelength excited photoluminescence spectroscopy of deep-level hole traps in Ga(In)NP
2015 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 117, 015701- p.Article in journal (Refereed) Published
By employing photoluminescence(PL) spectroscopy under dual-wavelength optical excitation, we uncover the presence of deep-level hole traps in Ga(In)NP alloys grown by molecular beam epitaxy(MBE). The energy level positions of the traps are determined to be at 0.56 eV and 0.78 eV above the top of the valance band. We show that photo-excitation of the holes from the traps, by a secondary light source with a photonenergy below the bandgapenergy, can lead to a strong enhancement (up to 25%) of the PL emissions from the alloys under a primary optical excitation above the bandgapenergy. We further demonstrate that the same hole traps can be found in various MBE-grown Ga(In)NP alloys, regardless of their growth temperatures, chemical compositions, and strain. The extent of the PL enhancement induced by the hole de-trapping is shown to vary between different alloys, however, likely reflecting their different trap concentrations. The absence of theses traps in the GaNP alloy grown by vapor phase epitaxy suggests that their incorporation could be associated with a contaminant accompanied by the N plasma source employed in the MBEgrowth, possibly a Cu impurity.
Place, publisher, year, edition, pages
2015. Vol. 117, 015701- p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-113961DOI: 10.1063/1.4905274ISI: 000347958600065OAI: oai:DiVA.org:liu-113961DiVA: diva2:785901