On the origin of the 2.2–2.3eV photoluminescence from chemically etched germanium

Kartopu, Giray; Bayliss, S. C.; Karavanskiĭ, V. A.; Curry, Richard J.; Turan, Raşit; Sapelkin, Andrei V.

doi:10.1016/s0022-2313(02)00570-7

Cited by 40 publications

(34 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is also supported by the lack of an observable Raman signal related to the oxide. Possible presence of significant amorphous Ge content has been doubted in our previous study [18]. This is confirmed both by EXAFS and HP Raman studies.…”

Section: /Gpasupporting

confidence: 70%

See 1 more Smart Citation

Raman study of nano‐crystalline Ge under high pressure

Sapelkin

Karavanskiĭ

Kartopu

et al. 2007

Physica Status Solidi (b)

View full text Add to dashboard Cite

We investigated high pressure behaviour of nano‐crystalline Ge that is free of substrate up to 17 GPa using Raman scattering. Nano‐crystalline Ge has been prepared by stain‐etching of 100 oriented Ge wafer and then lifted off. Electron diffraction measurements revealed that after etching particles retain diamond structure of original mono‐crystalline wafer. The Raman peak corresponding to zone‐center optical phonons mode was found to be shifted at ambient conditions from 300 cm–1 found in c‐Ge to around 280(1) cm–1 in nano‐crystalline Ge. Particle size was estimated from Raman and TEM measurements to be ∼5 nm. We observed no pressure transformation from the diamond to a high pressure phase as expected for bulk Ge (at around 10 GPa) in our Raman measurements. The pressure dependence of the Raman peak position was found to be highly nonlinear with dω /dP = 3.9(1) cm–1/GPa and d2ω /dP2 = –0.14(2) cm–1/GPa2. We discuss the microscopic origins of observed high pressure behavior of nano‐crystalline Ge. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Section: /Gpasupporting

confidence: 70%

“…[18]. Presence of nano-crystalline Ge (nc-Ge) and its structure was confirmed by TEM and electron diffraction (Jeol JEM 2010 microscope) measurements (Fig.…”

Section: Originalmentioning

confidence: 85%

Raman study of nano‐crystalline Ge under high pressure

Sapelkin

Karavanskiĭ

Kartopu

et al. 2007

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…With increased deposition time, the samples show a decrease in peak intensity and an increase in FWHM, demonstrating that the quality of the GIs is reduced when heating time is increased. The peaks around 300 cm −1 are attributed to the optical phonon contribution of the Ge-Ge stretching mode [15]. The red-shifted trend for sample grown compared to that of the bulk Ge (300 cm −1 ) [16] is compatible with the previous XRD result, which suggests that the sample experienced tensile strain for 1 and 2 hour deposition and compressive strain for 3 hour heating times.…”

Section: Resultssupporting

confidence: 88%

Formation of Uniform Germanium Islands on Silicon Substrate Using Nickel as Catalyst by Thermal Evaporation Method

et al. 2015

View full text Add to dashboard Cite

Uniform germanium islands (GIs) were grown on Si (100) using a nickel layer as catalyst through the physical vapor deposition of germanium (Ge) powder at 1000• C at dierent deposition times. Prior to the deposition of Ge layer, nickel (Ni) catalyst was deposited on silicon substrates via radio frequency magnetron sputtering technique. Scanning electron microscopy results showed that the increase in deposition time resulted in a variation in surface morphology. Energy dispersive X-ray spectrometer analysis found that the GI samples composed of Ni element indicating the role of Ni in uniform Ge islands formation. The X-ray diraction pattern spectra revealed that the GIs exhibited a Ge cubic structure and the intensity of Ge peaks varies with deposition time. In-plane strain indicated that the strain caused by the substrate is tensile and changed to compressive strain at the longer deposition time. The Raman spectra exhibited a red shift in the Ge-Ge peak, compared with the bulk Ge, as a result of compressive strain of the GIs. Fourier transform infrared spectrum analysis also indicated that the optical band gap Eg values of GIs can be varied by deposition time.

show abstract

“…Previous studies suggest, at least, three possibilities for several PL peaks appearing at 1.8 -2.3 eV, which are non-bridging oxygen hole center (≡Ge-O·) [27], self-trapped exciton [28], and nano-crystalline Ge [26,[29][30][31][32].…”

mentioning

confidence: 99%

Photo-induced phenomena in GeO2 glass

Terakado

Tanaka

2006

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

Photo-induced changes in GeO2 glass have been studied in optical and structural properties. Band-gap excitation gives rise to modifications in mid-gap optical absorption and photo-luminescence spectrum. It also produces electron-spin signals at g ≃ 1.995 and 2.008.Raman-scattering spectrum becomes sharper, x-ray diffraction patterns show disappearance of a crystalline peak, and illuminated surfaces expand. These observations can be accounted for by assuming bond transformations from rutile-like to defective quartz-like structures and/or from small to large rings. These photo-induced changes in GeO2 are comparatively discussed with those in SiO2 and GeS2.

show abstract

On the origin of the 2.2–2.3eV photoluminescence from chemically etched germanium

Cited by 40 publications

References 22 publications

Raman study of nano‐crystalline Ge under high pressure

Raman study of nano‐crystalline Ge under high pressure

Formation of Uniform Germanium Islands on Silicon Substrate Using Nickel as Catalyst by Thermal Evaporation Method

Photo-induced phenomena in GeO2 glass

Contact Info

Product

Resources

About