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Cathodoluminescence efficiency dependence on excitation density in n-type gallium nitride.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Phillips, Matthew R. Telg, Hagen Kucheyev, Sergei O. Gelhausen, Olaf Toth, Milos |
| Copyright Year | 2003 |
| Abstract | Cathodoluminescence (CL) spectra from silicon doped and undoped wurtzite n-type GaN have been measured in a SEM under a wide range of electron beam excitation conditions, which include accelerating voltage, beam current, magnification, beam diameter, and specimen temperature. The CL intensity dependence on excitation density was analyzed using a power-law model (I CL proportional, variant J m ) for each of the observed CL bands in this material. The yellow luminescence band present in both silicon and undoped GaN exhibits a close to cube root (m = 0.33) dependence on electron beam excitation at both 77 K and 300 K. However, the blue (at 300 K) and donor-acceptor pair (at 77 K) emission peaks observed in undoped GaN follow power laws with exponents of m = 1 and m = 0.5, respectively. As expected from its excitonic character, the near band edge emission intensity depends linearly (m = 1) in silicon doped GaN and superlinearly (m = 1.2) in undoped GaN on the electron beam current. Results show that the intensities of the CL bands are highly dependent not only on the defect concentration but also on the electron-hole pair density and injection rate. Furthermore, the size of the focussed electron beam was found to have a considerable effect on the relative intensities of the CL emission peaks. Hence SEM parameters such as the objective lens aperture size, astigmatism, and the condenser lens setting must also be considered when assessing CL data based on intensity measurements from this material. |
| Starting Page | 6 |
| Ending Page | 6 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://opus.lib.uts.edu.au/bitstream/10453/715/1/2003000319.pdf |
| PubMed reference number | 12639240v1 |
| Volume Number | 9 |
| Issue Number | 2 |
| Journal | Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Bands CDISC SEND Biospecimens Terminology Cube Dosage Form Dependence Diameter (qualifier value) Excitation Exhibits as Topic Gallium 67 citrate Silicon electron beam gallium nitrate luminescence voltage |
| Content Type | Text |
| Resource Type | Article |
