Emerging Light‐Emitting Materials for Photonic Integration

Abstract

Nowadays, apart from data communication and telecommunication, photonic integrated systems also show great potential in bio/chemical sensing, medical imaging, and spectroscopy. [5-14] Benefit from mature complementary metal-oxide-semiconductor (CMOS) technology in the past two decades, many high-performance key components in photonic integrated systems have been realized, such as low-loss waveguides, ultrafast modulators, and large bandwidth photodetectors. [15-17] However, the lack of efficient light sources presents a huge roadblock and significantly slows down the progress of photonic integration. In terms of energy efficiency and scalability, on-chip light sources greatly surpass the off-chip light sources. [18] On-chip coupling allows flexible layouts and highdensity integration without introducing extra packaging cost and off-chip coupling losses. An ideal on-chip light source should satisfy the following requirements: emission at communication wavelengths, e.g. 850, 1310, or 1550 nm; continuous wave (CW) operation via electrical pumping at room temperature; high output power with low energy consumption, i.e., high efficiency and low threshold; CMOS-compatible fabrication techniques. Because of the poor radiative recombination efficiency of silicon, researchers have turned their attention to germanium-on-silicon (Ge-on-Si) and III-V-on-silicon (III-V-on-Si) lasers, which have been summarized in the literature. [19-21] Although the above-mentioned requirements may be relaxed to some extent according to different application scenarios, these new light sources have also encountered various difficulties and challenges on the way to practical applications (see Section 2). Therefore, it is still necessary and urgent to identify alternatives for the photonic integrated system. In the past 10 years, 2D materials and metal halide perovskites are undoubtedly two rising stars in the semiconductor field. These emerging materials with unique properties are widely used in optoelectronic devices, such as solar cells, photodetectors, light-emitting diodes (LEDs), and lasers. [22,34] Especially in the application of on-chip light sources, these materials show some advantages over Ge and III-V semiconductors. Both 2D materials and metal-halide perovskites have a variety of low-cost preparation methods. Both of them can be easily integrated on foreign substrates. More importantly, 2D materials and metal-halide perovskites own novel and charming luminescence properties. These materials with diverse energy bandgaps cover a broad spectral range, [22,35-37] which implies that the emission wavelength can be selected to accommodate different applications. Great advances of 2D material and The arrival of the information explosion era is urging the development of large-bandwidth high-data-rate optical interconnection technology. Up to now, the biggest stumbling block in optical interconnections has been the lack of efficient light sources despite significant progress that has been made in germanium-on-silicon (Ge-on-Si) and III-V-on-...

Hexagonal Si−Ge Class of Semiconducting Alloys Prepared by Using Pressure and Temperature

“…[12,31] Moreover this work offers a chemical solution to a pressing engineering problem. [31,45] Namely to produce hexagonal SiGe, that is not templated and free of substrate attachments in order to be able to develop optoelectronic devices with pure hex-SiGe and Si integrated on the same chip. We have produced here bulk hexagonal SiGe.…”

Cover Feature: Hexagonal Si−Ge Class of Semiconducting Alloys Prepared by Using Pressure and Temperature (Chem. Eur. J. 57/2021)

“…[12,31] Moreover this work offers a chemical solution to a pressing engineering problem. [31,45] Namely to produce hexagonal SiGe, that is un-templated, rid of substrate attachments in order to be able to develop optoelectronic devices with pure hex-SiGe and Si integrated on the same chip. We produce here pure and bulk hexagonal SiGe.…”

The making of a reconfigurable semiconductor with a soft ionic lattice

“…Analogous to electronic circuits, the essential building blocks of PIC may include optical amplifiers, phase shifters, polarization converters, and waveguides. 82 There-fore, integration of all these components critically depends on the growth and engineering of multiple types of semiconductors on Si. However, the material incompat-ibility of Si with traditional semiconductors (e.g., III-V compounds) has been the greatest barrier to further development of Si-integrated photonics.…”