Voltage-matched, monolithic, multi-band-gap devices

A monolithic, tandem photonic device comprising:

• a first layer of semiconductor material having an in-type region, a p-type region, a first band-gap energy, and a plurality of sub-cells formed therein;
• a second layer of semiconductor material having an n-type region, a p-type region, a second band-gap energy, and a plurality sub-cells formed therein;
• and
• a plurality of sub-cell strings, each of the plurality of sub-cell strings comprising two or more electrically interconnected sub-cells;
• wherein the plurality of sub-cell strings are electrically connected to one another in parallel.

A two-terminal, monolithic, tandem light emitting diode (LED) device comprising:

• a first layer of semiconductor material having an n-type region, a p-type region, and a first band-gap energy;
• a plurality of first layer LED sub-cells formed in the first layer and electrically connected to form a two-terminal first layer sub-cell string;
• a second layer of semiconductor material having an n-type region, a p-type region, and a second band-gap energy;
• and
• a plurality of second layer LED sub-cells formed in the second layer and electrically connected to form a two-terminal second layer sub-cell, wherein the first layer sub-cell string and the second layer sub-cell string are separately electrically biased, and wherein the first band-gap energy and the second band gap-energy are not equivalent in value.

A two-terminal, monolithic, tandem photonic device comprising:

• a first layer of semiconductor material having an n-type region, a p-type region, and a first band-gap energy;
• a plurality of first layer sub-cells formed in the first layer along a first axis and electrically connected in series to form a first layer sub-cell string;
• a second layer of semiconductor material having an n-type region, a p-type region, and a second band-gap energy;
• and
• a plurality of second layer sub-cells formed in the second layer along a second axis that is not perpendicular with the first axis and electrically connected in series to form a second layer sub-cell string, wherein the first layer sub-cell string and the second layer sub-cell string are electrically connected in parallel to form the two-terminal, monolithic, tandem photonic device.

A method of forming a multi-layer photonic semiconductor device, the method comprising the steps of:

• forming a first layer of semiconductor material having a first band-gap energy on a substrate, the first layer including a first conductivity-type region and a second conductivity-type region on a substrate;
• forming a second layer of semiconductor material having a second band-gap energy on the first layer, the second layer including a first conductivity-type region and a second conductivity-type region;
• forming a plurality of isolation trenches through the first and second layers;
• forming a plurality of electrical interconnects at least partially within the isolation trenches between conductivity-type regions in the first layer of semiconductor material;
• and
• forming a plurality of electrical interconnects at least partially within the isolation trenches between conductivity-type regions in the second layer of semiconductor material.

A method of forming a photonic semiconductor device in a semiconductor structure having at least two semiconductor layers, each semiconductor layer including a first conductivity-type region and a second conductivity-type region, the method comprising the steps of:

• forming a plurality of isolation trenches through the first and second semiconductor layers, the isolation trenches dividing the semiconductor structure into a plurality of sub-cell stacks, each stack including a sub-cell formed in the first semiconductor layer arid a sub-cell formed in the second semiconductor layer;
• forming a plurality of first layer electrical interconnects at least partially within the isolation trenches between conductivity-type regions of sub-cells formed in the first semiconductor layer;
• and
• forming a plurality of second layer electrical interconnects at least partially within the isolation trenches between conductivity-type regions of sub-cells formed in the second semiconductor layer.

A method of forming a two terminal, photonic device in a semiconductor structure having at least a first semiconductor layer and a second semiconductor layer, each semiconductor layer including a first conductivity-type region and a second conductivity-type region, the method comprising the steps of:

• forming a plurality of first layer sub-cells in the first semiconductor layer along a first axis;
• electrically connecting the plurality of first layer sub-cells in series to form a first layer sub-cell string;
• forming a plurality of second layer sub-cells in the second semiconductor layer along a second axis that is not perpendicular with the first axis;
• electrically connecting the plurality of second layer sub-cells in series to form a second layer sub-cell string;
• and
• electrically connecting the first layer sub-cell string and the second layer sub-cell strings together in parallel.