University of California

Nanovision Biosciences, Inc.

Yu-Hsin Liu

Yu-Hwa Lo

Yuchun Zhou

David Lawrence Hall

Lujiang Yan

Samir Damle

Zihan Xu

Nicholas W Oesch

Optoelectronic retinal prostheses transduce light into electrical current for neural stimulation. A novel optoelectronic pixel architecture is presented comprising a vertically integrated photo junction field-effect-transistor (Photo-JFET) and neural stimulating electrode. Experimental measurements demonstrate that optically addressed Photo-JFET pixels utilize phototransistive gain to produce a broad range of neural stimulation current and can effectively stimulate retinal neurons in vitro. The compact nature of the Photo-JFET pixel can enable high resolution retinal prostheses with a theoretical visual acuity ˜20/60 to help restore vision in patients with degenerative retinal diseases.

Retinal prostheses

Methods, systems, and devices are disclosed for low noise and high efficiency photoelectric amplification based on cycling excitation process (CEP). In some aspects, a device for amplifying signals of light-induced photocurrent includes an anode connected to a positive terminal of a voltage source; a disordered material layer coupled to the anode, wherein the disordered material layer is structured to have a thickness of 100 nm or less; and a cathode coupled to the disordered material layer and connected to a negative terminal of the voltage source, in which the device is operable to amplify photoexcited carriers based on photon absorption to produce an external quantum efficiency of the device that is at least 100%.

Systems, devices and methods for amplification of signals based on a cycling excitation process in disordered materials

Methods, systems, and devices are disclosed for implementing high conversion efficiency solar cells. In one aspect, an optical-to-electrical energy conversion device includes a substrate formed of a doped semiconductor material and having a first region and a second region, an array of multilayered nanoscale structures protruding from the first region of the substrate, in which the nanoscale structures are formed of a first co-doped semiconductor material covered by a layer of a second co-doped semiconductor material forming a core-shell structure, the layer covering at least a portion of the doped semiconductor material of the substrate in the second region, and an electrode formed on the layer-covered portion of the substrate in the second region, in which the multilayered nanoscale structures provide an optical active region capable of absorbing photons from light at one or more wavelengths to generate an electrical signal presented at the electrode.

Highly efficient optical to electrical conversion devices and MElHODS

A semiconductor device capable of enhanced sub-bandgap photon absorption and detection is described. This semiconductor device includes a p-n junction structure formed of a semiconductor material, wherein the p-n junction structure is configured such that at least one side of the p-n junction (p-side or n-side) is spatially confined in at least one dimension of the device (e.g., the direction perpendicular to the p-n junction interface). Moreover, at least one side of the p-n junction (p-side or n-side) is heavily doped. The semiconductor device also includes electrical contacts formed on a semiconductor substrate to apply an electrical bias to the p-n junction to activate the optical response at target optical wavelength corresponds to an energy substantially equal to or less than the energy band-gap of the first semiconductor material. In particular embodiments, the semiconductor material is silicon.

Growing community of inventors

San Diego, CA, United States of America

Yu-Hsin Liu