Effect of hydrogenation on room-temperature 1.54 μm Er3+ photoluminescent properties of erbium-doped silicon-rich silicon oxide

Abstract

The effect of hydrogenation on the room-temperature 1.54 μm Er3+ photoluminescent properties of erbium-doped silicon-rich silicon oxide thin films is investigated. Two samples with 7 and 1 at. % excess silicon and 0.4 at. % erbium were prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition of SiH4 and O2 with cosputtering of erbium and subsequent rapid thermal anneal at 900 °C. Hydrogenation by exposure to D plasma doubles the 1.54 μm Er3+ luminescence intensity from the high excess silicon content sample but halves that from the low excess silicon content sample. The lifetimes and excitation power dependence of Er+ luminescence show that hydrogenation primarily affects the active erbium fraction, increasing it in case of the high excess silicon sample but decreasing it in case of the low excess silicon content sample. With proper treatments, Er3+ luminescence lifetime of over 7 ms is obtained.

Photoluminescence excitation spectroscopy of erbium-doped silicon-rich silicon oxide

“…However, other researchers have directly observed Si nanocrystals of 2-3 nm in diameter in a similarly prepared SRSO film using transmission electron microscopy, 16 and we have previously confirmed the presence of such Si nanocrystals in a comparable erbiumdoped SRSO film using x-ray diffraction and PL. 12,17 Zhao et al have reported that erbium doped into amorphous Si can act as nucleation centers and result in Si nanocrystal formation after an anneal of only 10 s at 700°C, 18 and a similar effect may be operating here. Er 3ϩ PL measurements were made using either a HeCd laser, an Ar laser, or a Ti:sapphire laser as the excitation source, and using either a liquid nitrogen cooled Ge detector or a thermo-electrically cooled In-GaAs detector and employing the standard lock-in technique.…”

Flashlamp pumping of erbium‐doped silicon nanoclusters

“…The nature of this exchange is unclear, but agrees qualitatively with similar observations published by this and other groups working on erbium-doped crystalline and porous silicon, silicon nanopowders, and chalcogenide glasses. [1][2][3][4][5][6][7][8]15,16 It is unlikely that the exchange proceeds via defect states, as there is a strong dependence of the strength of coupling on the excess silicon content of the films, and samples exhibiting very little defect luminescence also exhibit strong indirect excitation of the optically active erbium fraction. High concentrations of silicon lead to shorter erbium luminescent lifetimes and flatter PLE spectra, consistent with the assumption of an increased probability of interaction between nanoclusters and erbium ions.…”

“…Recently, erbium-doped nanoclustered or porous silicon has shown considerable promise, and there have been a number of studies, including those by this group, showing that an efficient exchange mechanism exists between the silicon host and rare-earth ion which transfers broad-band optical or electrical excitation into narrow-band emission at 1.53 mm. [1][2][3][4][5][6][7][8] Such materials exhibit efficient erbium luminescence and offer the advantages of ease of processing and convenient integration with current semiconductor manufacturing technology.…”

Thermal annealing effects on photoluminescence properties of carbon-doped silicon-rich oxide thin films implanted with erbium

“…7,40,41 It was generally observed that H passivation can increase luminescence intensity for both Si nanocrystals and Er ions in Sirich oxides. 7,40,41 It was generally observed that H passivation can increase luminescence intensity for both Si nanocrystals and Er ions in Sirich oxides.…”