Formation of ultra-thin Ge1−xSnx/Ge1−x−ySixSny quantum heterostructures and their electrical properties for realizing resonant tunneling diode

Abstract

Huge thermal noise owing to the narrow energy bandgap is one of the critical issues for group IV-based photonics in the mid-infrared regime. With this motivation, we examined to form Ge1−xSnx/Ge1−x−ySixSny quantum heterostructures (QHs) by molecular beam epitaxy for realizing resonant tunneling diodes composed of group-IV materials. We confirmed the formation of approximately 2 nm-thick Ge1−xSnx/Ge1−x−ySixSny QHs with atomically flat interfaces by x-ray diffraction and transmission electron microscopy methods. Moreover, by the current density–voltage (J–V) measurement at 10 K, we observed the occurrence of a non-linear distinct hump in the J–V characteristic, which is possibly originated from quantum transport of heavy holes. According to the tunneling transmission spectra simulation result, the hump property would be due to two possible scenarios: a resonant tunneling of heavy holes in the QH and/or a resonance phenomenon that heavy holes pass just above a potential barrier.

Monolithic infrared silicon photonics: The rise of (Si)GeSn semiconductors

“…26 However, the integration of SiGeSn/GeSn heterostructures in devices is still at an early stage. 27 While an increased optical emission is expected for SiGeSn/GeSn multi-quantum well (MQW) heterostructures, the band offset must be sufficiently large to be effective for room-temperature operation.…”

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,[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.…”