Emcore Corporation

Applied Solar Energy Corporation

Tecstar Power Systems, Inc.

Tecstar Power System, Inc.

Milton Y Yeh

Frank F Ho

Chaw-Long Chu

Peter A Iles

Peter A IIes

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

Semiconductor body forming a solar cell with a bypass diode

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.

High efficiency solar cell

Growing community of inventors

Santa Monica, CA, United States of America

Milton Y Yeh