| Author(s): |
John B. Schlager; Kristine A. Bertness; Paul T. Blanchard; Lawrence H. Robins; Alexana Roshko; Norman A. Sanford; |
| Title: |
Steady-state and time-resolved photoluminescence from relaxed and strained GaN nanowires grown by catalyst-free molecular-beam epitaxy |
| Published: |
June 24, 2008 |
| Abstract: |
We report steady-state and time-resolved photoluminescence (TRPL) measurements on individual GaN nanowires (6-20 micrometers in length, 30-940 nm in diameter) grown by nitrogen-plasma-assisted, catalyst-free MBE on Si(111) and dispersed onto fused quartz substrates. Induced tensile strain for nanowires bonded to fused silica and compressive strain for nanowires coated with atomic-layer-deposition alumina led to redshifts and blueshifts of the dominant steady-state PL emission peak, respectively. Unperturbed nanowires exhibited spectra associated with high-quality, strain-free material. The TRPL lifetimes, which were similar for both relaxed and strained nanowires of similar size, ranged from 200 ps to over 2 ns, compared well with those of low-defect bulk GaN, and depended linearly on nanowire diameter. The diameter-dependent lifetimes yielded a room-temperature surface recombination velocity S of 9X103 cm/s for our silicon-doped GaN nanowires. |
| Citation: |
Journal of Applied Physics |
| Volume: |
103 |
| Issue: |
124309 |
| Pages: |
pp. 124309-1 - 124309-6 |
| Keywords: |
gallium nitride;molecular beam epitaxy;nanowire;photoluminescence;strain;time-resolved photoluminescence |
| Research Areas: |
Nanowires |
| PDF version: |
 Click here to retrieve PDF version of paper (518KB) |
