All-Group IV membrane room-temperature mid-infrared photodetector

Abstract

Strain engineering has been a ubiquitous paradigm to tailor the electronic band structure and harness the associated new or enhanced fundamental properties in semiconductors. In this regard, semiconductor membranes emerged as a versatile class of nanoscale materials to control lattice strain and engineer complex heterostructures leading to the development of a variety of innovative applications. Herein we exploit this quasi-two-dimensional platform to tune simultaneously the lattice parameter and bandgap energy in group IV GeSn semiconductor alloys. As Sn content is increased to reach a direct band gap, these semiconductors become metastable and typically compressively strained. We show that the release and transfer of GeSn membranes lead to a significant relaxation thus extending the absorption wavelength range deeper in the mid-infrared. Fully released Ge${}_{0.83}$Sn${}_{0.17}$ membranes were integrated on silicon and used in the fabrication of broadband photodetectors operating at room temperature with a record wavelength cutoff of 4.6 $\mu$m, without compromising the performance at shorter wavelengths down to 2.3 $\mu$m. These membrane devices are characterized by two orders of magnitude reduction in dark current as compared to devices processed from as-grown strained epitaxial layers. The latter exhibit a content-dependent, shorter wavelength cutoff in the 2.6-3.5 $\mu$m range, thus highlighting the role of lattice strain relaxation in shaping the spectral response of membrane photodetectors. This ability to engineer all-group IV transferable mid-infrared photodetectors lays the groundwork to implement scalable and flexible sensing and imaging technologies exploiting these integrative, silicon-compatible strained-relaxed GeSn membranes.

References in corpus (5)

• Integrated near-field thermo-photovoltaics for on-demand heat recycling
• Band structure of strained Ge${}_{1-x}$Sn${}_x$ alloy: a full-zone 30-band $k\cdot p$ model
• Band structure of Ge${}_{1-x}$Sn${}_x$alloy: a full-zone 30-band $k$$\cdot$$p$ model
• Vacancy complexes in nonequilibrium germanium-tin semiconductors
• Decoupling the effects of composition and strain on the vibrational modes of GeSn

Cited by in corpus (9)

• Monolithic Infrared Silicon Photonics: The Rise of (Si)GeSn Semiconductors
• GeSn Defects and their Impact on Optoelectronic Properties: A Review
• Dark current in monolithic extended-SWIR GeSn PIN photodetectors
• Mid-infrared emission and absorption in strained and relaxed direct bandgap GeSn semiconductors
• Extended-SWIR Photodetection in All-Group IV Core/Shell Nanowires
• Recrystallization and Interdiffusion Processes in Laser-Annealed Strain-Relaxed Metastable Ge${}_{0.89}$Sn0${}_{.11}$
• Transfer-printed multiple Ge${}_{0.89}$Sn${}_{0.11}$ membrane mid-infrared photodetectors
• Micrometer-thick, atomically random Si0.06Ge0.90Sn0.04 for silicon-integrated infrared optoelectronics
• Ge-Ge${}_{0.92}$Sn${}_{0.08}$ core-shell single nanowire infrared photodetector with superior characteristics for on-chip optical communication