Direct epitaxial growth of III-V light sources on Si photonic chips is promising to realize low-cost and high-functionality photonic integrated circuits. Historically, high temperature reliability of such devices has been the major roadblock due to crystalline defects from heteroepitaxy. Here, by reducing the threading dislocation densities to ∼ 1 × 1 0 6 c m − 2 and efficiently removing misfit dislocations above and below the active region, 1.3 µm InAs quantum-dot lasers directly grown on industry standard on-axis Si (001) show record-breaking reliability at 80°C. The hero device shows minimum degradation after more than 1200 h of constant current stress. Statistical analysis shows an extrapolated lifetime of over 22 years for the median devices, bringing these devices one big step closer to real world applications.

Powder bed binder jet printing is an additive manufacturing method in which powder is deposited layer-by-layer and selectively joined in each layer with binder. Since the powder does not melt during printing, the density after printing is about 50%, and sintering is needed to densify as-printed parts. In this study, we investigate the effect of sintering temperature on density, microstructure, phase formation and mechanical properties of power bed binder jet printed alloy 625 parts. To determine the sintering temperatures, the as-received powder was subjected to differential scanning calorimetry analysis, and printed samples were cured and sintered at various temperatures under high vacuum. Density measurements, elemental analysis, phase formation and microstructure of as-printed, cured and sintered samples were investigated compared with mechanical properties. Results indicate that a fully densified parts with densities of up to 99.6%, as well as favorable mechanical properties (hardness of up to 238 HV 0.1 and UTS of up to 612 MPa) may be obtained for the sample sintered at 1280 °C. It is concluded that alloy 625 produced by powder bed binder jet printing can achieve similar density and mechanical properties as cast alloy 625.

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With recent developments in high‐speed and high‐power electronics and Si‐based photonic integration, the concept of monolithic III–V/Si integration through epitaxial methods is gaining momentum. However, the performance and reliability of epitaxially grown devices are still limited by defects in the semiconductor material, especially the threading dislocation density (TDD). Herein, a novel “asymmetric step‐graded filter” structure grown by molecular beam epitaxy (MBE) is proposed based on a systematic study of the commonly used techniques for threading dislocation reduction for high‐quality GaAs on Si (001) growth. The proposed structure greatly enhances the plastic relaxation in the filter layers. A surface TDD lower than 2 × 106 cm−2 is achieved with a total buffer thickness of only 2.55 μm. This provides a clear pathway to further reduce defect density down to the theoretical limit in the 105 cm−2 regime with a thin buffer structure.

Monolithic integration of quantum dot (QD) gain materials onto Si photonic platforms via direct epitaxial growth is a promising solution for on-chip light sources. Recent developments have demonstrated superior device reliability in blanket hetero-epitaxy of III–V devices on Si at elevated temperatures. Yet, thick, defect management epi designs prevent vertical light coupling from the gain region to the Si-on-Insulator waveguides. Here, we demonstrate the first electrically pumped QD lasers grown by molecular beam epitaxy on a 300 mm patterned (001) Si wafer with a butt-coupled configuration. Unique growth and fabrication challenges imposed by the template architecture have been resolved, contributing to continuous wave lasing to 60 °C and a maximum double-side output power of 126.6 mW at 20 °C with a double-side wall-plug efficiency of 8.6%. The potential for robust on-chip laser operation and efficient low-loss light coupling to Si photonic circuits makes this heteroepitaxial integration platform on Si promising for scalable and low-cost mass production.