University of California

Wai Son Ko

Connie J Chang-Hasnain

Chih-Wei Chuang

Forrest G Sedgwick

Roger Chen

Kar Wei Ng

Thai-Truong Du Tran

Forrest Grant Sedgwick, Iv

Monolithically integrated optical resonators are disclosed. An optical resonator may be a nanopillar optical resonator that is formed directly on a substrate and promotes a helically-propagating cavity mode. The helically-propagating cavity mode may result in significant reflection or, total internal reflection at an interface of the nanopillar optical resonator and the substrate even if refractive indices of the nanopillar optical resonator and the substrate are the same or similar. As a result, strong optical feedback, and thus strong resonance, may be provided in the nanopillar optical resonator.

Nanopillar optical resonator

The present disclosure provides a catalyst-free growth mode of defect-free Gallium Arsenide (GaAs)-based nanoneedles on silicon (Si) substrates with a complementary metal-oxide-semiconductor (CMOS)-compatible growth temperature of around 400&#xb0; C. Each nanoneedle has a sharp 2 to 5 nanometer (nm) tip, a 600 nm wide base and a 4 micrometer (&#x3bc;m) length. Thus, the disclosed nanoneedles are substantially hexagonal needle-like crystal structures that assume a 6&#xb0; to 9&#xb0; tapered shape. The 600 nm wide base allows the typical micro-fabrication processes, such as optical lithography, to be applied. Therefore, nanoneedles are an ideal platform for the integration of optoelectronic devices on Si substrates. A nanoneedle avalanche photodiode (APD) grown on silicon is presented in this disclosure as a device application example. The APD attains a high current gain of 265 with only 8V bias.

Nanoneedle plasmonic photodetectors and solar cells

The present disclosure provides a method for a catalyst-free growth mode of defect-free Gallium Arsenide (GaAs)-based nanoneedles on silicon (Si) substrates with a complementary metal-oxide-semiconductor (CMOS)-compatible growth temperature of around 400&#xb0; C. Each nanoneedle has a sharp 2 to 5 nanometer (nm) tip, a 600 nm wide base and a 4 micrometer (&#x3bc;m) length. Thus, the disclosed nanoneedles are substantially hexagonal needle-like crystal structures that assume a 6&#xb0; to 9&#xb0; tapered shape. The 600 nm wide base allows the typical micro-fabrication processes, such as optical lithography, to be applied. Therefore, nanoneedles are an ideal platform for the integration of optoelectronic devices on Si substrates. A nanoneedle avalanche photodiode (APD) grown on silicon is presented in this disclosure as a device application example. The APD attains a high current gain of 265 with only 8V bias.

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Menlo Park, CA, United States of America

Wai Son Ko