Explore the vast range of titles available.

The explosion of artificial intelligence, the possible end of Moore's law, dawn of quantum computing, and the continued exponential growth of data communications traffic have brought new urgency to the need for laser integration on the diversified Si platform. While diode lasers on group III‐V platforms have long‐powered internet data communications and other optoelectronic technologies, direct integration with Si remains problematic. A paradigm‐shifting solution requires exploring new and unconventional materials and integration approaches. In this work, it is shown that a sub‐10‐nm ultra‐thin Si1−xGex buffer layer fabricated by an oxidative solid‐phase epitaxy process can facilitate extraordinarily efficient strain relaxation. The Si1−xGex layer is formed by ion implanting Ge into Si(111) and selectively oxidizing Si atoms in the resulting ion‐damaged layer, precipitating a fully strain‐relaxed Ge‐rich layer between the Si substrate and surface oxide. The efficient strain relaxation results from the high oxidation temperature, producing a periodic network of dislocations at the substrate interface, coinciding with modulations of the Ge content in the Si1−xGex layer and indicating the presence of defect‐mediated diffusion of Si through the layer. The epitaxial growth of high‐quality GaAs is demonstrated on this ultra‐thin Si1−xGex layer, demonstrating a promising new pathway for integrating III‐V lasers directly on the Si platform. Sub‐10‐nm‐thick strain‐relaxed Si1−xGex buffer layers are fabricated on Si by oxidative solid‐phase epitaxy and employed as a new platform for group III‐V heteroepitaxy on the Si platform. Si1−xGex/Si interface strain relaxation occurs via a periodic dislocation network coinciding with composition fluctuations, resulting from defect‐mediated diffusion of Si and Ge during oxidation.

Persistent surface charge retention in dielectric oxides is critical for a wide range of electronic and energy applications, including charge‐trapping memory devices, triboelectric generators, and supercapacitors. Since charge retention is intrinsically governed by charge diffusion, understanding and controlling the underlying diffusion mechanisms in charge‐storing materials remain significant challenges. Here, ultralong charge retention in epitaxially grown LaAlO3 (LAO) thin films is reported, enabled by anisotropic charge diffusion. The surface accumulation of oxygen vacancies, driven by the internal polar field, effectively suppresses out‐of‐plane electron hopping, allowing ≈90.9% of the initially injected charges to remain on the LAO surface after 180 h, with stable retention persisting for weeks or longer. Time‐resolved Kelvin probe force microscopy and finite‐difference simulations consistently reveal that this retention enhancement arises from diffusion anisotropy induced by surface‐localized defect states in LAO, rather than by isotropic ionic migration. These results provide an effective strategy for designing high‐performance charge storage materials based on polar‐layered oxides, paving the way for durable surface charge‐based electronic and energy devices. Anisotropic charge diffusion in epitaxially grown LAO thin films is reported, which enables ultralong charge retention. Surface‐accumulated oxygen vacancies effectively suppress out‐of‐plane electron hopping, allowing ≈90.9% of the surface charges to remain after a few weeks or longer. Kelvin probe force microscopy and finite‐difference simulations consistently support this mechanism for stable charge retention.