An optically pumped 2.5 μm GeSn laser on Si operating at 110 K

Abstract

This paper reports the demonstration of optically pumped GeSn edge-emitting lasers grown on Si substrates. The whole device structures were grown by an industry standard chemical vapor deposition reactor using the low cost commercially available precursors SnCl4 and GeH4 in a single run epitaxy process. Temperature-dependent characteristics of laser-output versus pumping-laser-input showed lasing operation up to 110 K. The 10 K lasing threshold and wavelength were measured as 68 kW/cm2 and 2476 nm, respectively. Lasing characteristic temperature (T0) was extracted as 65 K.

Mid-infrared light emission > 3 µm wavelength from tensile strained GeSn microdisks

“…Since overcoming a number of epitaxial growth challenges, direct bandgap GeSn alloys with 12.6 % Sn have been shown to be direct bandgap, and lasing has been demonstrated at low temperatures [16][17][18]. Lasing thresholds, however, remain large (>68 kW/cm 2 ), and strong thermal quenching is present above 110 K. [18] When grown on (100) Ge or Si substrates, GeSn alloys develop biaxial compressive strain, which partially counteracts the effect of the Sn alloying on the band-structure.…”

“…Lasing thresholds, however, remain large (>68 kW/cm 2 ), and strong thermal quenching is present above 110 K. [18] When grown on (100) Ge or Si substrates, GeSn alloys develop biaxial compressive strain, which partially counteracts the effect of the Sn alloying on the band-structure. This means that for the levels of Sn incorporation currently achievable for device grade alloys, there is an inherent need for strain relaxation in order to achieve a direct band-structure.…”

The thermal stability of epitaxial GeSn layers

“…[2][3][4] Nonetheless, in order to move toward real-market applications, several issues still have to be addressed such as the low laser operating temperature. In particular, an increase of the Sn content in the active material beyond ∼12 at.…”

Direct bandgap type-I GeSn/GeSn quantum well on a GeSn- and Ge- buffered Si substrate

“…[1][2][3][4][5][6][7][8][9] The successful demonstration of direct bandgap GeSn light emitting diodes (LEDs), and optically-pumped GeSn lasers, [10][11][12][13][14] indicates the great potential of GeSn for Si-based light sources. GeSn LEDs with double heterostructures (DHS) 11,[15][16][17][18][19][20][21][22] and quantum wells (QWs) [23][24][25][26][27][28][29][30][31] have been reported.…”

“…It is found that the Sn incorporation is highly sensitive to the starting growth surface. 12,39 Both the strain and the Sn composition in the starting surface can affect the Sn incorporation efficiency. As a result, when a nominal Ge 0.927 Sn 0.073 layer was grown on QW surface, the introduced strain impairs the Sn incorporation, leading to the formation of a 4.2 nm-thick Ge 0.965 Sn 0.035 interlayer between the GeSn well and top barrier.…”