Formation and optoelectronic property 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 a boron-ion-implanted Ge(001) substrate

Abstract

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.

Crystalline and optoelectronic properties of Ge1−x Sn x /high-Si-content-Si y Ge1−x−y Sn x double-quantum wells grown with low-temperature molecular beam epitaxy

“…Figure 2(a) shows PL spectra measured at room temperature (RT) for the single-QW samples with T SiGeSn of 100 • C, 150 • C, and 200 • C. The lower T SiGeSn sample showed a higher PL intensity. This suggests that the superior crystallinity of single-QW heterostructure results in an inherently efficient of the PL performance, which agrees with the discussion in our previous reports [22,28]. Moreover, the spectra of the samples with T SiGeSn of 100 and 150 • C show PL peaks around 0.57 eV and 0.65 eV, while that of the sample with T SiGeSn of 200 • C shows the PL peak around 0.65 eV.…”

Sn-incorporation effect on thermoelectric properties of Sb-doped Ge-rich Ge1−x−y Si x Sn y epitaxial layers grown on GaAs(001)

“…1(b)], the elemental contents (x and y) and the strain in the Ge 1−x−y Si x Sn y layers were estimated, as with the case of the previous study. 10) The detailed estimation method was described in the supplementary data. The sample specifications are summarized in Table I.…”

“…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.…”

Self-organized Ge1−x Sn x quantum dots formed on insulators and their room temperature photoluminescence

“…1) However, the E gΓ of the direct transition Ge 1−x Sn x bulk is less than 0.6 eV. To achieve luminescence preferable for the optical interconnect of LSIs, using quantum levels formed by lowering the dimensions of the light-emitting layers such as multi-quantum-wells (MQWs), 2,3) nanowires, 4,5) and QDs [6][7][8] is a feasible approach to realizing high E gΓ . Light sources based on high-density (>10 10 cm −2 ) QDs are particularly promising because of their lower power consumption and greater operational temperature stability compared to MQWs.…”