Experimental doping dependence of the lattice parameter in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>n</mml:mi></mml:math>-type Ge: Identifying the correct theoretical framework by comparison with Si

Xu, Chi; Senaratne, C. L.; Kouvetakis, John; Menéndez, José

doi:10.1103/physrevb.93.041201

Cited by 33 publications

(19 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Refinement of pristine Ge NCs PXRD gives rise to a lattice parameter in reasonable agreement with the bulk Ge value (5.658 Å). Lattice parameters for Ge NCs as a function of size have not been reported; as Sb is added, the lattice parameters increase, consistent with expectations for the size of the dopant and incorporation into the lattice . Because the NC size also increases with Sb, if there was no incorporation of Sb into the structure, one would not expect to see the lattice parameters increase.…”

Section: Resultssupporting

confidence: 55%

“…Lattice parameters for Ge NCs as a function of size have not been reported; as Sb is added, the lattice parameters increase, consistent with expectations for the size of the dopant and incorporation into the lattice. 44 Because the NC size also increases with Sb, if there was no incorporation of Sb into the structure, one would not expect to see the lattice parameters increase. The summary of crystallite sizes is provided in Table 1.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Structural Insights on Microwave-Synthesized Antimony-Doped Germanium Nanocrystals

Tabatabaei

Sully

et al. 2021

ACS Nano

View full text Add to dashboard Cite

Doped and alloyed germanium nanocrystals (Ge NCs) are potential candidates for a variety of applications such as photovoltaics and near IR detectors. Recently, bismuth (Bi) as an n-type group 15 element was shown to be successfully and kinetically doped into Ge NCs through a microwave-assisted solution-based synthesis, although Bi is thermodynamically insoluble in bulk crystalline Ge. To expand the composition manipulation of Ge NCs, another more common n-type group 15 element for semiconductors, antimony (Sb), is investigated. Oleylamine (OAm)- and OAm/trioctylphosphine (TOP)-capped Sb-doped Ge NCs have been synthesized by the microwave-assisted solution reaction of GeI2 with SbI3. Passivating the Ge surface with a binary ligand system of OAm/TOP results in formation of consistently larger NCs compared to OAm alone. The TOP coordination on the Ge surface is confirmed by 31P NMR and SEM-EDS. The lattice parameter of Ge NCs increases with increasing Sb concentration (0.00–2.0 mol %), consistent with incorporation of Sb. An increase in the NC diameter with higher content of SbI3 in the reaction is shown by TEM. XPS and EDS confirm the presence of Sb before and after removal of surface ligands with hydrazine and recapping the Ge NC surface with dodecanethiol (DDT). EXAFS analysis suggests that Sb resides within the NCs on highly distorted sites next to a Ge vacancy as well as on the crystallite surface. High Urbach energies obtained from photothermal deflection spectroscopy (PDS) of the films prepared from pristine Ge NC and Sb-doped Ge NCs indicate high levels of disorder, in agreement with EXAFS data. Electrical measurements on TiO2–NC electron- and hole-only devices show an increase in hole conduction, suggesting that the Sb-vacancy defects are behaving as a p-type dopant in the Ge NCs, consistent with the vacancy model derived from the EXAFS results.

show abstract

Section: Resultssupporting

confidence: 55%

Section: Resultsmentioning

confidence: 99%

Structural Insights on Microwave-Synthesized Antimony-Doped Germanium Nanocrystals

Tabatabaei

Sully

et al. 2021

ACS Nano

View full text Add to dashboard Cite

show abstract

“…This means that P can efficiently reduce the lattice parameter of GeSn:P and compensate the biaxial compressive strain. Even the electronic contribution which normally expands the lattice cannot compensate the effect of P doping [28]. According to the theoretical prediction the lattice contraction in Ge doped with P to the concentration of 1.2×10 20 cm -3 is in the range of 2 % [28].…”

Section: Samplementioning

confidence: 98%

“…Even the electronic contribution which normally expands the lattice cannot compensate the effect of P doping [28]. According to the theoretical prediction the lattice contraction in Ge doped with P to the concentration of 1.2×10 20 cm -3 is in the range of 2 % [28]. In our case, the highest P concentration in the GeSn layer is close to 5×10 20 cm -3 indicating a significant lattice contraction (close to 4 %) if the P lies in the substitutional position.…”

Section: Samplementioning

confidence: 99%

Strain and Band-Gap Engineering in Ge - Sn Alloys via P Doping

et al. 2018

View full text Add to dashboard Cite

Ge with a quasi-direct band gap can be realized by strain engineering, alloying with Sn or ultra-high n-type doping. In this paper, we use all three approaches together -strain engineering, Sn alloying and n-type doping to fabricate direct band gap GeSn alloys. The heavily-doped n-type GeSn was realized using a CMOS-compatible non-equilibrium material processing. P is used to form a highly-doped n-type GeSn layers and to modify the lattice parameter of GeSn:P alloys. The strain engineering in heavily P-doped GeSn films is confirmed by X-ray diffraction and micro-Raman spectroscopy. The change of the band gap in GeSn:P alloy as a function of P concentration is theoretically predicted using density functional theory and experimentally verified by near-infrared spectroscopic ellipsometry.According to the shift of the absorption edge it is shown that for an electron concentration above 1×10 20 cm -3 the band gap renormalization is partially compensated by the Burstein-Moss effect. These results indicate that Ge-based materials have a large potential for the nearinfrared optoelectronic devices, fully compatible with CMOS technology.

show abstract

“…24 In fact, the covalent radius of P (107 pm) is about 11% smaller than that of Ge. 38,39 This means that the heavily P-doped Ge layer made by ion implantation should exhibit biaxial tensile strain. The biaxial tensile strain in group IV semiconductors causes the blue shift of the TO Ge-Ge phonon mode, which is also visible in Figure 5(a).…”

Section: Journal Of Applied Physicsmentioning

confidence: 99%

Nanoscale n++-p junction formation in GeOI probed by tip-enhanced Raman spectroscopy and conductive atomic force microscopy

Prucnal

Berencén

Wang

et al. 2019

Journal of Applied Physics

View full text Add to dashboard Cite

Ge-on-Si and Ge-on-insulator (GeOI) are the most promising materials for the next-generation nanoelectronics that can be fully integrated with silicon technology. To this day, the fabrication of Ge-based transistors with a n-type channel doping above 5 × 10 19 cm −3 remains challenging. Here, we report on n-type doping of Ge beyond the equilibrium solubility limit (n e ≈ 6 × 10 20 cm −3 ) together with a nanoscale technique to inspect the dopant distribution in n ++ -p junctions in GeOI. The n ++ layer in Ge is realized by P + ion implantation followed by millisecond-flashlamp annealing. The electron concentration is found to be three times higher than the equilibrium solid solubility limit of P in Ge determined at 800°C. The millisecond-flashlamp annealing process is used for the electrical activation of the implanted P dopant and to fully suppress its diffusion. The study of the P activation and distribution in implanted GeOI relies on the combination of Raman spectroscopy, conductive atomic force microscopy, and secondary ion mass spectrometry. The linear dependence between the Fano asymmetry parameter q and the active carrier concentration makes Raman spectroscopy a powerful tool to study the electrical properties of semiconductors. We also demonstrate the high electrical activation efficiency together with the formation of ohmic contacts through Ni germanidation via a single-step flashlamp annealing process.

show abstract

Experimental doping dependence of the lattice parameter inn-type Ge: Identifying the correct theoretical framework by comparison with Si

Cited by 33 publications

References 48 publications

Structural Insights on Microwave-Synthesized Antimony-Doped Germanium Nanocrystals

Structural Insights on Microwave-Synthesized Antimony-Doped Germanium Nanocrystals

Strain and Band-Gap Engineering in Ge - Sn Alloys via P Doping

Nanoscale n++-p junction formation in GeOI probed by tip-enhanced Raman spectroscopy and conductive atomic force microscopy

Contact Info

Product

Resources

About