Pseudodirect to Direct Compositional Crossover in Wurtzite GaP/In x Ga 1-x P Core-Shell Nanowires

• Published in: Nano letters 2016-12, Vol.16 (12), p.7930-7936
• Main Authors: Gagliano, L, Belabbes, A, Albani, M, Assali, S, Verheijen, M A, Miglio, L, Bechstedt, F, Haverkort, J E M, Bakkers, E P A M
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.6b04242

Thanks to their uniqueness, nanowires allow the realization of novel semiconductor crystal structures with yet unexplored properties, which can be key to overcome current technological limits. Here we develop the growth of wurtzite GaP/In Ga P core-shell nanowires with tunable indium concentration and optical emission in the visible region from 590 nm (2.1 eV) to 760 nm (1.6 eV). We demonstrate a pseudodirect (Γ -Γ ) to direct (Γ -Γ ) transition crossover through experimental and theoretical approach. Time resolved and temperature dependent photoluminescence measurements were used, which led to the observation of a steep change in carrier lifetime and temperature dependence by respectively one and 3 orders of magnitude in the range 0.28 ± 0.04 ≤ x ≤ 0.41 ± 0.04. Our work reveals the electronic properties of wurtzite In Ga P.