Formation and characterization of Ge 1−x−y Si x Sn y /Ge 1−x Sn x /Ge 1−x−y Si x Sn y double heterostructures with strain-controlled Ge 1−x−y Si x Sn y layers

Self Cite

We have investigated the formation and optoelectronic properties of strain relaxed Ge 1−x−y Si x Sn y /Ge 1−x Sn x /Ge 1−x−y Si x Sn y double heterostructures on ion-implanted Ge substrates. The strain relaxation of Ge 1−x−y Si x Sn y and Ge 1−x Sn x epitaxial layers was achieved using an ionimplanted Ge substrate. The maximal degree of strain relaxation (DSR) of the Ge 1−x Sn x layers was evaluated to be 46%. In addition, we obtained a sharp and strong peak in the photoluminescence (PL) spectra from the sample with a DSR of 46%, while no strong peak was detected from a sample with a smaller DSR (22%). From the theoretical calculation of the energy band structure and the measurement temperature dependence of the PL intensity, the sharp and strong peak can be explained by the transition from an indirect to direct bandgap semiconductor due to the increase of the DSR and a concomitant increase of the Γ-valley electron population. Moreover, the PL intensity increases by the improvement of the crystallinity by a post deposition annealing process.

Section: Resultsmentioning

confidence: 80%

Section: Resultsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 85%

See 1 more Smart Citation

Formation and optoelectronic property of strain-relaxed Ge_1−x−ySi_xSn _y /Ge_1−xSn_x/Ge_1−x−ySi _x Sn_y double heterostructures on a boron-ion-implanted Ge(001) substrate

Fukuda

Rainko

Sakashita

et al. 2019

Self Cite

“…because of their controllable lattice constants and band gaps depending on the Si, Ge, and Sn contents. 9,10) To realize the control of them independently, Si 1-x-y Ge x Sn y ternary alloys have been focused and studied widely by means of the molecular beam epitaxy (MBE) [11][12][13] and the chemical vapor deposition (CVD). 14,15) It is known that the low solid solubility limit of Sn into Si (∼0.1 at%) and Ge (∼1 at%) 16) requires the non-equilibrium formation of Sn containing group-IV alloys.…”

Section: Introductionmentioning

confidence: 99%

SiSn mediated formation of polycrystalline SiGeSn

Shimura

Okado

Motofuji

et al. 2022

Self Cite

Si1-xSnx and Si1-x-yGexSny polycrystalline thin layers were grown using Sn nanodots as crystal nuclei. Si1-xSnx crystallization occurred around Sn nanodots, and the substitutional Sn content was estimated as high as 1.5%. In the case of the poly-Si1-x-yGexSny, Ge and Si were deposited simultaneously on the Sn nanodots, however, Ge was preferentially incorporated into the Sn nanodots, resulting in the formation of the poly-Si1-x-yGexSny with amorphous Si residue. It was found that the poly-Si1-xSnx formed by the Sn nanodots mediated formation can be used as the new virtual substrate to be alloyed with Ge, namely the 2step formation process consisting of poly-Si1-xSnx crystallization and Ge alloying with the Si1-xSnx is the effective formation process for the poly-Si1-x-yGexSny formation. This non-equilibrium process with achieving crystallization resulted in the substitutional Si and Sn content in the as-grown poly-Si1-x-yGexSny as high as 19.4% and 3.4%, respectively.

“…1,[3][4][5][6] This means that a quantum confinement structure suitable for device applications such as light-emitting diodes, semiconductor lasers, and high electron mobility transistors can be realized using only strain-free group-IV semiconductors. Several groups, including us, recently demonstrated the crystal growth of type-I band structures, specifically, Ge 1−x−y Si x Sn y /Ge junction, 7) Ge 1−x−y Si x Sn y /Ge 1−x Sn x / Ge 1−x−y Si x Sn y double heterojunctions, [8][9][10][11] and the multiquantum well. [12][13][14] They showed Ge 1−x−y Si x Sn y 's high potential for use in the cladding layers of lasers and resonant tunneling diodes.…”

Section: Introductionmentioning

confidence: 99%

Sn-incorporation effect on thermoelectric properties of Sb-doped Ge-rich Ge_1−x−ySi_xSn_y epitaxial layers grown on GaAs(001)

Kurosawa

Nakata²,

Zhan³

et al. 2022

Self Cite

We investigate Sn incorporation effects on the thermoelectrical characteristics of n-type Ge-rich Ge1−x−y Si x Sn y layers (x ≈ 0.05−0.1, y ≈ 0.03) pseudomorphically grown on semi-insulating GaAs(001) substrates by molecular beam epitaxy. Despite the low Sn content of 3%, the Sn atoms play a role in suppressing the thermal conductivity from 13.5 to 9.0 Wm−1K−1 without degradation of the electrical conductivity and the Seebeck coefficient. Furthermore, a relatively high power factor (maximum: 14 μWcm−1K−2 at room temperature) was also achieved for the Ge1−x−y Si x Sn y layers, almost the same as the Si1−x Ge x ones (maximum: 12 μWcm−1K−2 at room temperature) grown with the same conditions. This result opens up the possibility of developing Sn-incorporated group-IV thermoelectric devices.