NOVELTY - The manufacture method involves providing a semiconductor structure which includes an absorber layer (108) comprising of gallium arsenide. A bypass function is then provided in a p-n junction of the semiconductor structure. The p-n junction breaks down in a controlled manner by a Zener breakdown effect under reverse-bias conditions. The p-n junction breaks down by the Zener breakdown effect in an electric field having less magnitude than an electric field causing avalanche breakdown of the p-n junction.    USE - Photovoltaic device manufacture method for forming gallium arsenide based photovoltaic device (claimed). Can be used for fabricating e.g. solar cells.    ADVANTAGE - Provides for increased efficiency and production compatible method for providing bypass diode functionality in photovoltaic devices. Provides a bypass function in a gallium arsenide photovoltaic cell to allow bypass current to flow in mismatched conditions such as shading of some cells in a series string. Ensures that the self-bypass functionality allows protection of cells while avoiding the need for separate or distinct bypass diodes to be connected to the cells. Allows for greater efficiency and flexibility in resulting photovoltaic devices and in forming the photovoltaic devices when compared to conventional solar cell fabrication processes. Allows the functionality of a bypass diode to be included in a high-performance, gallium arsenide solar cell without having to fabricate or provide a separate bypass diode connected to the solar cells. Allows more common and low-cost photovoltaic cells to be produced using known techniques already used for gallium arsenide structures and cells. Allows greater design restrictions since the p-n junction can be designed without the restrictions of the high doping concentration needed for the self-bypass function.    DESCRIPTION OF DRAWING(S) - The drawing shows the cross-sectional view of a two-sided photovoltaic cell.    Front contact layer (105)    Absorber layer (108)    Photovoltaic cell (200)    Front metal contact layer (202)    Back metal contact layer (204)    Anti-reflective coating (206)