PHOTODETECTOR DEVICE HAVING LIGHT-COLLECTING OPTICAL MICROSTRUCTURE
A opto-electronic device includes a semiconductor device and a non-imaging optical concentrator on a surface of the semiconductor device. The semiconductor device has a substrate and a photodetector formed on a surface of the substrate. The non-imaging optical concentrator has a peripheral surface extending around a central region of the active area of the photodetector. The non-imaging optical concentrator redirects at least a portion of incoming light into the active area.
1 . An opto-electronic device, comprising:
a semiconductor device having a substrate and a photodetector formed on a surface of the substrate, the photodetector having an active area; and
a non-imaging optical concentrator on a surface of the semiconductor device, the non-imaging optical concentrator having a peripheral surface extending around a central region of the active area and redirecting at least a portion of incoming light into the active area.
2 . The opto-electronic device of claim 1 , wherein the peripheral surface has a tapering cross sectional shape.
3 . The opto-electronic device of claim 2 , wherein the peripheral surface has a circular cross-sectional shape.
4 . The opto-electronic device of claim 3 , wherein the non-imaging optical concentrator has a frusto-conical cavity region defining the peripheral surface, the cavity region having a wider end farther from the active area with respect to a direction parallel to an optical axis of the active area than a narrower end adjacent the active area, and the peripheral surface reflects light entering the cavity region at the wider end of the cavity region toward the active area.
5 . The opto-electronic device of claim 4 , wherein the peripheral surface comprises a metal film in the cavity region.
6 . The opto-electronic device of claim 3 , wherein the non-imaging optical concentrator has a frusto-conical solid region defining the peripheral surface, the solid region having a wider end farther from the active area with respect to a direction parallel to an optical axis of the active area than a narrower end adjacent the active area, and the peripheral surface reflects light entering the solid region at a wider end of the solid region toward the active area.
7 . The opto-electronic device of claim 3 , wherein the non-imaging optical concentrator has a frusto-conical solid region defining the peripheral surface, the solid region having a narrower end farther from the active area with respect to a direction parallel to an optical axis of the active area than a wider end adjacent the active area, and the peripheral surface refracts light entering the solid region through the peripheral surface toward the active area.
8 . The device of claim 2 , wherein the peripheral surface has a polygonal cross-sectional shape.
9 . The opto-electronic device of claim 8 , wherein the non-imaging optical concentrator has a frusto-polyhedral cavity region defining the peripheral surface, the cavity region having a wider end farther from the active area with respect to a direction parallel to an optical axis of the active area than a narrower end adjacent the active area, and the peripheral surface reflects light entering the cavity region at a wider end of the cavity region toward the active area.
10 . The opto-electronic device of claim 9 , wherein the peripheral surface comprises a metal film in the cavity region.
11 . The opto-electronic device of claim 9 , wherein the peripheral surface has a square cross-sectional shape.
12 . A method of operation in an opto-electronic device, the opto-electronic device comprising a semiconductor device and a non-imaging optical concentrator on a surface of the semiconductor device, the non-imaging optical concentrator having a peripheral surface extending around a central region of the active area the method comprising:
the non-imaging optical concentrator receiving incoming light; and
the peripheral surface of the non-imaging optical concentrator redirecting at least a portion of the incoming light into an active area of a photodetector formed on a surface of a substrate of the semiconductor device.
13 . The method of claim 12 , wherein the peripheral surface has a tapering cross sectional shape.
14 . The method of claim 13 , wherein the peripheral surface has a circular cross-sectional shape.
15 . The method of claim 14 , wherein the non-imaging optical concentrator has a frusto-conical cavity region defining the peripheral surface, the cavity region having a wider end farther from the active area with respect to a direction parallel to an optical axis of the active area than a narrower end adjacent the active area, and the peripheral surface reflects light entering the cavity region at the wider end of the cavity region toward the active area.
16 . The method of claim 15 , wherein the peripheral surface comprises a metal film in the cavity region.
17 . The method of claim 14 , wherein the non-imaging optical concentrator has a frusto-conical solid region defining the peripheral surface, the solid region having a wider end farther from the active area with respect to a direction parallel to an optical axis of the active area than a narrower end adjacent the active area, and the peripheral surface reflects light entering the solid region at a wider end of the solid region toward the active area.
18 . The method of claim 14 , wherein the non-imaging optical concentrator has a frusto-conical solid region defining the peripheral surface, the solid region having a narrower end farther from the active area with respect to a direction parallel to an optical axis of the active area than a wider end adjacent the active area, and the peripheral surface refracts light entering the solid region through the peripheral surface toward the active area.
19 . The method of claim 13 , wherein the peripheral surface has a polygonal cross-sectional shape.
20 . The method of claim 19 , wherein the non-imaging optical concentrator has a frusto-polyhedral cavity region defining the peripheral surface, the cavity region having a wider end farther from the active area with respect to a direction parallel to an optical axis of the active area than a narrower end adjacent the active area, and the peripheral surface reflects light entering the cavity region at a wider end of the cavity region toward the active area.