Monolithic Integration of Sub-50 nm III–V Nano-Heterostructures on Si (001) for Telecom Photonics

The demand for advanced photonics technology is increasing rapidly, fueled by the necessity for high-performance, cost-effective optical information processing systems extending into the quantum domain. Silicon, benefiting from its mature fabrication processes, stands as an ideal platform. However, its inherent indirect bandgap leads to inefficient light emission. The integration of III-V materials is essential to overcome this drawback. These materials are recognized for their efficient light emission and superior bandgap engineering, making them indispensable in photonics and beyond. Here, we present the monolithic integration of small-volume III-V nano-heterostructures with silicon via selective area epitaxy in pyramidal openings etched in (100)-oriented silicon substrate. Precise positioning of the nano-heterostructures is achieved using electron beam lithography. Atomic resolution imaging and chemical analysis confirm the epitaxial nature of InP growth, revealing well-defined heterointerfaces. Each structure incorporates an InAsP quantum dot-like active medium, and the correlation of the growth parameters with the nanoscale structure is analyzed using advanced electron microscopy. Eight-band k·p calculations demonstrate energy level quantization in three spatial dimensions. Optical characterization shows that heterostructure emission can be engineered to cover the entire telecom wavelength range. These InAsP/InP nano-heterostructures can serve as gain medium for silicon-based hybrid nano-lasers, nano-LEDs, and quantum light sources in telecom wavelength range.