Abstract
The occurrence of spontaneous lateral phase separation during thin film growth of AlxIn1-xP by metal-organic chemical vapor deposition was investigated using a combination of transmission electron microscopy and atom probe tomography to obtain a quantitative view of this phenomenon. An anisotropic and coherent composition modulation was observed in the nearly lattice-matched films deposited below 750°C with a quasi-linear amplification with thickness that was inversely proportional to the growth temperature. The periodicity of the modulation increased exponentially with the growth temperature. A comparison of photoluminescence from phase separated and homogenous direct band gap AlxIn1-xP deposited on metamorphic InyGa1-yAs graded buffers showed a lowering of peak-emission energy in accordance with the atom probe compositional characterization without any degradation in luminous intensity. Additionally, indications of carrier trapping in the low band gap regions were observed even at room-temperature. While some of these results are in qualitative agreement with theoretical models of kinetic instability in unstrained alloy growth in the literature, significant discrepancies remain.
Original language | American English |
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Article number | 115306 |
Number of pages | 11 |
Journal | Journal of Applied Physics |
Volume | 118 |
Issue number | 11 |
DOIs | |
State | Published - 21 Sep 2015 |
Bibliographical note
Publisher Copyright:© 2015 AIP Publishing LLC.
NREL Publication Number
- NREL/JA-5K00-65347
Keywords
- aluminium
- growth
- III-V semiconductors
- phase separation
- thin films
- transmission electron microscopy (TEM)