ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The structural, electrical, and optical properties of crystalline Si codoped with Er and O by molecular beam epitaxy (MBE) have been investigated in detail. Si:Er:O layers (∼250 nm thick) have been grown by MBE, realizing uniform dopant concentrations in the range 8×1018–1.5×1020 cm−3 for Er and up to 5×1020 cm−3 for O. The O:Er ratio was varied between 0 and ∼20. Samples have been subsequently annealed at 900 °C for 1 h. We observed that clear constraints to the Er and O contents exist in order to incorporate them in a good quality single crystal. We also found that the O:Er ratio represents the main parameter in determining the properties of this system. For instance, Er is observed to behave as a donor in MBE grown samples and the donor concentration increases with the O:Er ratio until a saturation regime is achieved for a ratio higher than 6–8. All the samples emit light at 1.54 μm and similar behavior is also found for the optical activation of the Er ions. The thermal process usually increases the number of light emitting Er ions which is also increased by increasing the O:Er ratio; however, for O:Er ratios higher than 6–8, no further activation is measured. In contrast, the most intense room temperature photoluminescence (PL) peak is obtained in samples having an O:Er ratio ∼2, for which PL temperature quenching is strongly reduced. Indeed, the coupling of these observations with structural measurements allows us to clearly identify the best conditions for an MBE grown Si:Er:O sample. These phenomena are investigated in detail and discussed. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1308093
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