NOVELTY - A multijunction solar cell circuit comprises a Schottky diode electrically connected across photovoltaic cells of multijunction solar cell structure to protect the photovoltaic cells against reverse biasing. The diode is formed at least in part from the substrate and a diode contact formed over the substrate.    USE - For digital devices.    ADVANTAGE - The diode on the solar cell provides protection against reverse bias.    DETAILED DESCRIPTION - A multijunction solar cell circuit comprises a substrate having a front surface and a back surface and selected to have a portion forming part of a Schottky diode; a multijunction solar cell structure overlaying at least a portion of the front surface of the substrate; and a Schottky diode. The multijunction solar cell structure includes a first photovoltaic cell having a first photoactive junction and a second photovoltaic cell having a second photoactive junction overlaying at least a portion of the first photovoltaic cell. The Schottky diode is electrically connected across the photovoltaic cells to protect the cells against reverse biasing. It is formed at least in part from the substrate and a diode contact formed over the substrate. INDEPENDENT CLAIMS are included for the following:    (a) a method of manufacturing a protected multijunction solar cell circuit by selecting a substrate having a front surface, a back surface and at least a portion capable of forming a Schottky diode; forming a multijunction solar cell structure over at least a portion of the front surface of the substrate; forming a diode contact over the substrate at the portion capable of forming a Schottky diode; and electrically connecting a Schottky diode formed at the interface between the diode contact and the substrate across the photovoltaic cells to protect the photovoltaic cells against reverse biasing; and    (b) a semiconductor device comprising a substrate having first side and second side; a multijunction having at least a top layer and a bottom layer in contact with the first side of the substrate; a contact deposited on the top side of the multijunction; a bypass diode having first and second terminals deposited on another portion of the first side of the substrate; a first connection wire coupled between the contact and the first terminal of the bypass diode; and a second connection wire coupled between the second terminal of the bypass diode and the first side of the substrate.    DESCRIPTION OF DRAWING(S) - The figure shows layers of a multijunction solar cell structure formed over a substrate.