Emcore Corporation

Tecstar Power Systems, Inc.

Blue Photonics Inc.

Tecstar Power System, Inc.

Peter A Iles

Frank F Ho

Milton Y Yeh

Chaw-Long Chu

Yea-Chuan Milton Yeh

Frank Ho

The present invention is directed to systems and methods for protecting a solar cell. The solar cell includes first solar cell portion. The first solar cell portion includes at least one junction and at least one solar cell contact on a backside of the first solar cell portion. At least one bypass diode portion is epitaxially grown on the first solar cell portion. The bypass diode has at least one contact. An interconnect couples the solar cell contact to the diode contact.

Solar cell having an integral monolithically grown bypass diode

In one embodiment, a method of forming a multijunction solar cell having lattice mismatched layers and lattice-matched layers comprises growing a top subcell having a first band gap over a growth semiconductor substrate. A middle subcell having a second band gap is grown over the top subcell, and a lower subcell having a third band gap is grown over the middle subcell. The lower subcell is substantially lattice-mismatched with respect to the growth semiconductor substrate. The first band gap of the top subcell is larger than the second band gap of the middle subcell. The second band gap of the middle subcell is larger than the third band gap of the lower subcell. A support substrate is formed over the lower subcell, and the growth semiconductor substrate is removed. In various embodiments, the multijunction solar cell may further comprise additional lower subcells. A parting layer may also be provided between the growth substrate and the top subcell in certain embodiments. Embodiments of this reverse process permit the top and middle subcells to have high performance by having atomic lattice spacing closely matched to that of the growth substrate. Lower subcells can be included with appropriate band gap, but with lattice spacing mismatched to the other subcells. The reduced performance caused by strain resulting from mismatch can be mitigated without reducing the performance of the upper subcells.

High efficiency, monolithic multijunction solar cells containing lattice-mismatched materials and methods of forming same

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Arcadia, CA, United States of America

Peter A Iles