Time-resolved D-band luminescence in strain-relieved SiGe/Si

Fukatsu, S.; Mera, Yutaka; Inoue, Masaaki; Maeda, Koji; Akiyama, Hidefumi; Sakaki, H.

doi:10.1063/1.116284

Cited by 73 publications

(52 citation statements)

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“…The The energy separations (∼30 meV, as seen from Tables I and II), and general appearance of these peaks is reminiscent of PL that has been attributed to the presence of various dislocation defects (i.e., the four so-called D lines) in Si [13][14][15][16] and SiGe alloys. 17,18 The observed stronger PL features are in the right energy range for dislocations, if one extrapolates their possible line positions from those of silicon.…”

mentioning

confidence: 97%

Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si_0.4Ge_0.6

Lockwood

Rowell

Favre

et al. 2018

ECS J. Solid State Sci. Technol.

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Both Si and Ge possess indirect band gaps, which makes them very inefficient light emitters. One way to overcome this limitation is through bandgap engineering. M. d'Avezac et al. predicted in 2012 that a strained SiGe 2 Si 2 Ge 2 SiGe n super unit cell on Si 0.4 Ge 0.6 would have a direct and dipole-allowed gap of 0.863 eV, which is suited for optical fiber applications. Here we report on the epitaxial growth of such a structure and its optical properties, for which purpose two similar samples were prepared by molecular beam epitaxy and solid phase epitaxy. Photoluminescence (PL) spectra were obtained at low temperatures (6-25 K) with excitation at wavelengths of 405 and 458 nm, which emphasize the light emission from the sample superstructure. A strong low-energy PL quadruplet is seen, with peaks near 727, 758, 792 and 822 meV at 6 K, together with a much weaker peak at 871 meV. The ratio of intensities of the strong and weak peaks is the same in both samples. The weak peak at 871 meV is assigned to the dipole-allowed direct-gap transition associated with the super unit cell. The four strong peaks are attributed to dislocation related emission lines of the thick relaxed Si 0.4 Ge 0.6 transition layer.

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mentioning

confidence: 97%

Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si_0.4Ge_0.6

Lockwood

Rowell

Favre

et al. 2018

ECS J. Solid State Sci. Technol.

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“…This indicates that the PL at 0.92 eV decays much faster than the 0.8 eV PL (Kamenev et al, 2005). It is noteworthy from the crystal quality point of view that in both the CW and time-resolved experiments no PL associated with crystallographic dislocations (Fukatsu et al, 1996) was found.…”

Section: Interpretation Based On Interfacial Recombinationmentioning

confidence: 77%

“…Figure 16A also shows that the 0.8 eV PL rise time of ~2-3 μs is much longer than the exciting laser pulse duration of ~6 ns. This exceptionally long PL rise time could be associated with a special kind of Auger-assisted carrier spatial redistribution in the Si/SiGe NSs that is termed the Auger fountain (Ohnesorge et al, 1996;Lee et al, 2009 (Zrenner et al, 1995;Fukatsu et al, 1996;Kamenev et al, 2005). The stretched exponential PL decay phenomenon has been observed in a wide variety of systems apart from Si/SiGe NSs and it provides a good empirical fit to the data, although it most likely has no fundamental significance (Kuskovsky et al, 1998).…”

Section: Interpretation Based On Interfacial Recombinationmentioning

confidence: 99%

Si/SiGe Heterointerfaces in One-, Two-, and Three-Dimensional Nanostructures: Their Impact on SiGe Light Emission

Lockwood

Baribeau

et al. 2016

Front. Mater.

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Fast optical interconnects together with an associated light emitter that are both compatible with conventional Si-based complementary metal-oxide-semiconductor (CMOS) integrated circuit technology is an unavoidable requirement for the next-generation microprocessors and computers. Self-assembled Si/Si1−xGex nanostructures (NSs), which can emit light at wavelengths within the important optical communication wavelength range of 1.3-1.55 μm, are already compatible with standard CMOS practices. However, the expected long carrier radiative lifetimes observed to date in Si and Si/Si1−xGex NSs have prevented the attainment of efficient light-emitting devices, including the desired lasers. Thus, the engineering of Si/ Si1−xGex heterostructures having a controlled composition and sharp interfaces is crucial for producing the requisite fast and efficient photoluminescence (PL) at energies in the range of 0.8-0.9 eV. In this paper, we assess how the nature of the interfaces between SiGe NSs and Si in heterostructures strongly affects carrier mobility and recombination for physical confinement in three dimensions (corresponding to the case of quantum dots), two dimensions (corresponding to quantum wires), and one dimension (corresponding to quantum wells). The interface sharpness is influenced by many factors, such as growth conditions, strain, and thermal processing, which in practice can make it difficult to attain the ideal structures required. This is certainly the case for NS confinement in one dimension. However, we demonstrate that axial Si/Ge nanowire (NW) heterojunctions (HJs) with a Si/ Ge NW diameter in the range 50-120 nm produce a clear PL signal associated with bandto-band electron-hole recombination at the NW HJ that is attributed to a specific interfacial SiGe alloy composition. For three-dimensional confinement, the experiments outlined here show that two quite different Si1−xGex NSs incorporated into a Si0.6Ge0.4 wavy superlattice structure display PL of high intensity while exhibiting a characteristic decay time that is up to 1000 times shorter than that found in conventional Si/SiGe NSs. The non-exponential PL decay found experimentally in Si/SiGe NSs can be interpreted as resulting from variations in the separation distance between electrons and holes at the Si/SiGe heterointerface. The results demonstrate that a sharp Si/SiGe heterointerface acts to reduce the carrier radiative recombination lifetime and increase the PL quantum efficiency, which makes these SiGe NSs favorable candidates for future light-emitting device applications in CMOS technology.

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“…The emission at 0.995 eV and at 0.807 eV coincides to the energies of so-called D1 and D4 lines and may be attributed to the presence of dislocations in implanted layers. The dislocation-related PL peaks with maxima at 0.807 eV (D1) and at 0.870 eV (D2) were detected in plastically deformed Si [4], Er- -implanted silicon [3], relaxed epitaxial SiGe layers [5], laser-melted Si [6] and liquid-phase epitaxy Si [7]. The dislocation-related peaks at 0.935 (D3) and at 0.997 eV (D4) were found in Si wafers after the formation of oxygen precipitates [8].…”

Section: Resultsmentioning

confidence: 99%

Nanocrystal- and Dislocation-Related Luminescence in Si Matrix with InAs Nanocrystals

et al. 2011

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We have studied the influence of ion implantation and post-implantation annealing regimes on the structural and optical properties of silicon matrix with ion-beam synthesized InAs nanocrystals. (100) Si wafers were implanted at 25 and 500• C, subsequently with high fluences of As and In ions. After implantation the samples were processed by furnace and rapid thermal annealing at 900, 950 and 1050• C. A part of the samples implanted at 25• C was additionally exposed to H + 2 ions (100 keV, 1.2 × 10 16 cm −2 in terms of atomic hydrogen). This procedure was performed to obtain an internal getter. In order to characterize the implanted samples transmission electron microscopy and low-temperature photoluminescence techniques were employed. It was demonstrated that by introducing getter, varying the ion implantation temperature, ion fluences and post-implantation annealing duration, and temperature it is possible to form InAs nanocrystals in the range of sizes of 2-80 nm and create various concentration and distribution of different types of secondary defects. The last ones cause in turn the appearance in photoluminescence spectra dislocation-related D1, D2 and D4 lines at 0.807, 0.870 and 0.997 eV, respectively.

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Time-resolved D-band luminescence in strain-relieved SiGe/Si

Cited by 73 publications

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Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si_0.4Ge_0.6

Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si_0.4Ge_0.6

Si/SiGe Heterointerfaces in One-, Two-, and Three-Dimensional Nanostructures: Their Impact on SiGe Light Emission

Nanocrystal- and Dislocation-Related Luminescence in Si Matrix with InAs Nanocrystals

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Time-resolved D-band luminescence in strain-relieved SiGe/Si

Cited by 73 publications

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Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si0.4Ge0.6

Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si0.4Ge0.6

Si/SiGe Heterointerfaces in One-, Two-, and Three-Dimensional Nanostructures: Their Impact on SiGe Light Emission

Nanocrystal- and Dislocation-Related Luminescence in Si Matrix with InAs Nanocrystals

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Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si_0.4Ge_0.6

Direct-Gap Photoluminescence from a Si-Ge Multilayer Super Unit Cell Grown on Si_0.4Ge_0.6