Exciton dynamics at a single dislocation in GaN probed by picosecond time-resolved cathodoluminescence

Journal Article · Mon Jul 25 00:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4959832· OSTI ID:22594438

Carlin, J. -F.; Grandjean, N.; Deveaud, B.

We investigate the dynamics of donor bound excitons (D°X{sub A}) at T = 10 K around an isolated single edge dislocation in homoepitaxial GaN, using a picosecond time-resolved cathodoluminescence (TR-CL) setup with high temporal and spatial resolutions. An ∼ 1.3 meV dipole-like energy shift of D°X{sub A} is observed around the dislocation, induced by the local strain fields. By simultaneously recording the variations of both the exciton lifetime and the CL intensity across the dislocation, we directly assess the dynamics of excitons around the defect. Our observations are well reproduced by a diffusion model. It allows us to deduce an exciton diffusion length of ∼24 nm as well as an effective area of the dislocation with a radius of ∼95 nm, where the recombination can be regarded as entirely non-radiative.

• OSTI ID: 22594438
• Journal Information: Applied Physics Letters, Vol. 109, Issue 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CATHODOLUMINESCENCE
DEFECTS
DIFFUSION
DIFFUSION LENGTH
DIPOLES
EDGE DISLOCATIONS
EXCITONS
GALLIUM NITRIDES
MEV RANGE 01-10
PROBES
RECOMBINATION
SPATIAL RESOLUTION
STRAINS
TIME RESOLUTION