Optoelectronic semiconductor device and method of fabrication
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsYi Cui, Jia Zhu, Ching-Mei Hsu, Shanhui Fan, Zongfu Yu
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Abstract
An optoelectronic device comprising an optically active layer that includes a plurality of domes is presented. The plurality of domes is arrayed in two dimensions having a periodicity in each dimension that is less than or comparable with the shortest wavelength in a spectral range of interest. By virtue of the plurality of domes, the optoelectronic device achieves high performance. A solar cell having high energy-conversion efficiency, improved absorption over the spectral range of interest, and an improved acceptance angle is presented as an exemplary device.
Claims32
An article comprising:
- a substrate comprising a first plurality of surface features that is arranged in a first arrangement that is periodic in two dimensions, wherein the periodicity in at least one dimension is based on a wavelength of light within a spectral range of interest;
- a first composite layer disposed on the substrate, the first composite layer comprising a plurality of domes that is arranged in the first arrangement, wherein the first composite layer is an optically active layer that is characterized by a first band-gap wavelength, λbg1;
- and
- a first layer that is substantially reflective for light having a wavelength within the range of approximately 400 nm to approximately 1600 nm, the first layer being between the substrate and the first composite layer, and the first layer comprising a second plurality of surface features that is arranged in the first arrangement, wherein the second plurality of surface features is operative for enhancing light-absorption in the first composite layer.
A method comprising:
- providing a substrate having an array of projections that is arranged in a first arrangement that is periodic in two dimensions;
- forming a first layer on the substrate such that the first layer includes a plurality of surface features that are arranged in the first arrangement, wherein the first layer is substantially reflective for light having a wavelength within the range of approximately 400 nm to approximately 1600 nm;
- and
- forming a first composite layer disposed on the first layer, wherein the first composite layer comprises a plurality of domes, each of the plurality of domes being formed on a different one of the array of projections, and wherein the first composite layer is an optically active layer this is characterized by a first band gap wavelength, λbg1.
Dependencies are inferred from the claim text.