Photoluminescence and capacitance–voltage characterization of GaAs surface passivated by an ultrathin GaN interface control layer
| Autor: | Hideki Hasegawa, S Sanguan Anantathanasarn |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Materials science
Photoluminescence Passivation business.industry Fermi level Analytical chemistry General Physics and Astronomy Quantum yield Surfaces and Interfaces General Chemistry Condensed Matter Physics Surfaces Coatings and Films Characterization (materials science) symbols.namesake symbols Optoelectronics Quantum efficiency business Spectroscopy Layer (electronics) |
| Zdroj: | Applied Surface Science. 190:343-347 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/s0169-4332(01)00840-6 |
| Popis: | A novel surface passivation technique for GaAs using an ultrathin GaN interface control layer (GaN ICL) formed by surface nitridation was characterized by ultrahigh vacuum (UHV) photoluminescence (PL) and capacitance–voltage (C–V) measurements. The PL quantum efficiency was dramatically enhanced after being passivated by the GaN ICL structure, reaching as high as 30 times of the initial clean GaAs surface. Further analysis of PL data was done by the PL surface state spectroscopy (PLS3) simulation technique. PL and C–V results are in good agreement indicating that ultrathin GaN ICL reduces the gap states and unpins the Fermi level, realizing a wide movement of Fermi level within the midgap region and reduction of the effective surface recombination velocity by a factor of 1/60. GaN layer also introduced a large negative surface fixed charge of about 1012 cm−2. A further improvement took place by depositing a Si3N4 layer on GaN ICL/GaAs structure. |
| Databáze: | OpenAIRE |
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