Thin-Film Vapor-Liquid-Solid Growth of Compound Semiconductors on Heteroepitaxial and Amorphous Substrates

We demonstrate the versatility of a previously developed low-cost thin-film vapor-liquid-solid (TF-VLS) compound semiconductor growth technique. Specifically, we show that the quality of compound semiconductors grown via this technique enables a variety of optoelectronic and energy devices with geometries and material combinations unavailable to traditional vapor-phase growth techniques. Critically, this is enabled by the confinement of a liquid metal solvent layer, enabling precise control over the position and shape of nuclei on non-epitaxial and hetero-epitaxial substrates simply by controlling the shape of the solvent. Unlike vapor-phase processes, in which control over the shape of a growing nuclei is extremely challenging and primarily defined by the growth rates of various crystal facets, the TF-VLS process enables full control over nuclei, enabling fabrication of single crystal and ultra-large grain polycrystalline compound semiconductors regardless of substrate microstructure. This control over the material is then utilized to demonstrate compound semiconductor devices for energy harvesting, photon generation, and photon detection.