Ultrafast Exciton Dynamics in InGaN/GaN and Rh/Cr2O3 Nanoparticle-Decorated InGaN/GaN Nanowires

Ying-Chih Pu; M G Kibria; Zetian Mi; Jin Z Zhang

doi:10.1021/acs.jpclett.5b00909

Ultrafast Exciton Dynamics in InGaN/GaN and Rh/Cr2O3 Nanoparticle-Decorated InGaN/GaN Nanowires

J Phys Chem Lett. 2015 Jul 2;6(13):2649-56. doi: 10.1021/acs.jpclett.5b00909. Epub 2015 Jun 24.

Authors

Ying-Chih Pu¹, M G Kibria², Zetian Mi², Jin Z Zhang¹

Affiliations

¹ †Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States.
² ‡Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Québec H3A 0E9, Canada.

PMID: 26266748
DOI: 10.1021/acs.jpclett.5b00909

Abstract

Ultrafast exciton and charge-carrier dynamics in InGaN/GaN nanowires (NWs) with and without Rh/Cr2O3 nanoparticle (NP) decoration have been investigated using femtosecond transient absorption (TA) techniques with excitation at 415 nm and white-light probe (450-700 nm). By comparing the TA profiles between InGaN/GaN and InGaN/GaN-Rh/Cr2O3 NWs, an additional decay component on the medium time scale (∼50 ps) was identified with Rh/Cr2O3 decoration, which is attributed to interfacial charge transfer from InGaN/GaN NWs to Rh/Cr2O3 NPs, desired for light energy conversion applications. This is consistent with reduced photoluminescence (PL) of the NWs by the Rh/Cr2O3 NPs. A kinetic model was developed to explain the TA results and gain further insight into the exciton and charge-carrier dynamics.

Keywords: InGaN/GaN; charge transfer; dynamics; excited states; nanowires.