GeSn p-i-n detectors integrated on Si with up to 4% Sn

Abstract

GeSn heterojunction photodetectors on Si substrates were grown with Sn concentration up to 4%, fabricated for vertical light incidence, and characterized. The complete layer structure was grown by means of ultra low temperature (100 °C) molecular beam epitaxy. The Sn content shifts the responsivity into the infrared, about 310 nm for the 4% Sn sample. An increase of the optical responsivity for wavelengths higher than 1550 nm can be observed with increasing Sn content. At 1600 nm, the optical responsivity is increased by more than a factor of 10 for the GeSn diode with 4% Sn in comparison to the Ge reference diode.

Ultra-high-speed lateral solid phase crystallization of GeSn on insulator combined with Sn-melting-induced seeding

“…[5][6][7] However, high-quality GeSn films were recently grown on insulators by SPC; 15 in this experiment, doping the a-Ge films with Sn decreased their SPC temperature. Though these experiments only tested a narrow range of Sn concentrations (0.2%À2.0%), doping with 2% Sn decreased the SPC temperature by 50 C.…”

“…These velocities are 10 4 -10 8 Crystalline Ge-based group IV semiconductors are attractive for high-performance electrical and optical devices because Ge and GeSn alloys have higher carrier mobility than Si and because the band structure of GeSn can be engineered by changing the Sn concentration. [1][2][3][4][5][6][7] Especially interesting is that GeSn alloys with Sn concentrations exceeding 10% are expected to have direct band gaps. 4 To use these materials in flexible system-in-displays, high-speed thin-film transistors and high-efficiency thin-film solar cells must be fabricated on flexible plastic substrates.…”

Optical Characterization of Si-Based Ge1−x Sn x Alloys with Sn Compositions up to 12%

“…1 Among the various material systems that could be integrated on Si, the Ge 1Àx Sn x alloy has attracted much attention recently due to the following reasons: (1) Capability of monolithic integration on Si; 2 (2) Availability of direct bandgap material; 3 and (3) tunable bandgap covering broad shortwave-and mid-infrared (IR) wavelength range. 4 During the last decade, the GeSn-based optically pumped laser, 5 light emitting diode, [6][7][8][9][10][11][12] photo detector [13][14][15][16][17][18][19][20] have been demonstrated, and the GeSn modulator has been investigated 21,22 which make up a complete set of components for Si photonics. For these prototype devices, the material characteristics have turned out to be the decisive factor for the performance of the device.…”

Signal-to-noise ratio for a Ge-GeSn-GeSn Hetero PhotoTransistors at 1.55 µm

“…The alloy may show direct gap for Sn concentration exceeding 8% or by applying tensile strain [2]. Many workers in recent years are trying to exploit the direct gap of the alloy to develop lasers [4] or photodetectors [5][6][7][8].…”