Emcore Corporation

The Boeing Company

Applied Solar Energy Corporation

Blue Photonics Inc.

Tecstar Power System, Inc.

Frank F Ho

Milton Y Yeh

Chaw-Long Chu

Peter A Iles

Yea-Chuan Milton Yeh

Charles Hyunsang Suh

Peter A IIes

An IMM solar cell and an associated method of fabricating an IMM solar cell are provided. In the context of a method, a first subcell may be formed upon a temporary substrate and a second subcell may be formed upon the first subcell. The second subcell may have a smaller band gap than the first subcell. The method may also bond the first and second subcells to a silicon subcell and then remove the temporary substrate. In the context of an IMM solar cell, the IMM solar cell includes first and second subcells with the first subcell disposed upon the second subcell and the second subcell having a smaller band gap than the first subcell. The IMM solar cell may also include a silicon subcell supporting the first and second subcells thereupon with a metal-to-metal bond between the silicon subcell and the second subcell.

Inverted metamorphic multi-junction (IMM) solar cell and associated fabrication method

A solar cell structure including a silicon carrier defining a front side and a back side, and including an N-type portion having an exposed portion on the front side of the carrier and a P-type portion having an exposed portion on the front side of the carrier, the N-type portion and the P-type portion defining a P-N junction, and a solar cell defining a front side and a back side, wherein the solar cell is connected to the front side of the carrier such that the back side of the solar cell is electrically coupled to the exposed portion of the N-type portion, and wherein the front side of the solar cell is electrically coupled to the exposed portion of the P-type portion.

Solar cell structure including a silicon carrier containing a by-pass diode

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

Semiconductor body forming a solar cell with a 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

A high efficiency solar cell comprises: (a) a germanium substrate having a front surface and a back surface; (b) a back-metal contact on the back surface of the germanium substrate; (c) a first semiconductor cell comprising (1) a GaAs p-n junction formed from an n-GaAs and a p-GaAs layer, the n-GaAs layer formed on the front surface of the n-germanium substrate, and (2) a p-(Al,Ga)As window layer, the p-(Al,Ga)As window layer formed on the p-GaAs layer; (d) a tunnel diode comprising a GaAs p.sup.+ -n.sup.+ junction formed from a p.sup.+ -GaAs layer and an n.sup.+ -GaAs layer, the p.sup.+ -GaAs layer formed on the p-(Al,Ga)As window layer; and (e) a second semiconductor cell comprising (1) a (Ga,In)P p-n junction formed from an n-(Ga,In)P layer and a p-(Ga,In)P layer, the n(Ga,In)P layer formed on the n.sup.+ -GaAs layer of the tunnel diode, (2) a p-(Al,In)P window or contact layer formed on the p-(Ga,In)P layer, (3) metal grid lines contacting either the p-(Ga,In)P layer or the p-(Al,In)P layer, and (4) at least one anti-reflection coating layer covering the (Al,In)P layer. The cascade cell of the invention permits achieving actual efficiencies of over 23%.

High efficiency multi-junction solar cell

A gallium-arsenide solar cell has a germanium substrate cut at a special angle, with its surface generally perpendicular to the 001 axis, but tilted by about six to fifteen degrees toward the direction generally about half-way between the 011 and the 111 axial directions. To avoid the cascade effect the junction with the substrate may be passivated or photovoltaically inhibited by initiating vapor deposition of GaAs at a temperature below 700.degree. C. and rapidly ramping the temperature up to normal vapor deposition temperatures. Poisoning of the GaAs layer by germanium may be prevented inexpensively by using a silicon dioxide coating on one side of the germanium substrate.

Growing community of inventors

Yorba Linda, CA, United States of America

Frank F Ho