Effect of hydrogen chloride etching on carrier recombination processes of indium phosphide nanowires
| Autor: | Xiaojun Su, Wei Zhang, Zeng Xulu, Xianshao Zou, Arkady Yartsev, Hynek Němec, Magnus T. Borgström |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
education.field_of_study
Photoluminescence Materials science Population Nanowire 02 engineering and technology Trapping 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry.chemical_compound chemistry Chemical physics Etching (microfabrication) Ultrafast laser spectroscopy Indium phosphide General Materials Science Charge carrier 0210 nano-technology education |
| Zdroj: | Nanoscale. 11:18550-18558 |
| ISSN: | 2040-3372 2040-3364 |
| Popis: | Introduction of in situ HCl etching to an epitaxial growth process has been shown to suppress radial growth and improve the morphology and optical properties of nanowires. In this paper, we investigate the dynamics of photo-generated charge carriers in a series of indium phosphide nanowires grown with varied HCl fluxes. Time resolved photo-induced luminescence, transient absorption and time resolved terahertz spectroscopy were employed to investigate charge trapping and recombination processes in the nanowires. Since the excitation photons generate charges predominantly in less than a half length of the nanowires, we can selectively assess the charge carrier dynamics at their top and bottom. We found that the photoluminescence decay is dominated by the decay of the mobile hole population due to trapping, which is affected by the HCl etching. The hole trapping rate is in general faster at the top of the nanowires than at the bottom. In contrast, electrons remain highly mobile until they recombine non-radiatively with the trapped holes. The slowest hole trapping as well as the least efficient non-radiative recombination was recorded for etching using the HCl molar fraction of χHCl = 5.4 × 10-5. |
| Databáze: | OpenAIRE |
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