Work

Adaptive Epitaxy of C‐Si‐Ge‐Sn: Customizable Bulk and Quantum Structures

Year: 2025

Type: article

Abstract: The successful demonstration of (Si)Ge 1‐x Sn x alloys as direct‐gap materials for infrared lasers has driven intense research on group IV‐based devices for nanoelectronics, energy harvesting, and quantum computing applications. The material palette of direct‐gap group‐IV alloys can be further extended by introducing carbon to fine‐tune their structural and electronic properties, significantly expanding their functionality. This work presents heteroepitaxial growth of C(Si)GeSn alloys using an industry‐standard reduced‐pressure chemical vapor deposition reactor. The introduction of CBr 4 as a precursor enables controlled incorporation of C atoms (<1 at.%) into the epilayer lattice, while simultaneously increasing the Sn content in the CGeSn alloy up to ≈18 at.%. Carbon plays a key role in modulating strain, stabilizing the crystal structure, and influencing material properties. By leveraging alloying and strain engineering, quaternary CSiGeSn bulk layers and CGeSn/GeSn heterostructures are epitaxially grown. The impact of C incorporation on optical emission is investigated in LEDs based on CGeSn/GeSn multiple quantum wells, demonstrating enhanced near‐infrared emission at 2.54 µm, which is sustained up to room temperature.

Source: Advanced Materials

DOI: 10.1002/adma.202506919