TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The solar device further comprises a well in the multi-junction solar cell structure to provide electrical separation between the sub-cells and the bypass diode; a shunt having a first and second contacting ends; a stop etch layer deposited over the lateral conduction layer; a first contact layer deposited adjacent the bypass diode; a second contact layer disposed adjacent the substrate; and an n-doped gallium arsenic (GaAs) cap layer. The first contacting end of the shunt is connected to the lateral conduction layer. The second contacting end of the shunt is connected to the substrate via the well. The substrate is the Ge substrate. The multi-junction solar cell structure is a triple junction solar cell. The first sub-cell is a bottom solar cell. The second sub-cell is a middle solar cell. The third sub-cell is a top solar cell. The bottom solar cell includes a p-doped Ge base layer deposited over the substrate; an n-doped Ge emitter layer deposited or formed by diffusion over the base layer; and an n-doped nucleation layer deposited over the emitter layer.The middle solar cell includes a p-doped back surface field (BSF) layer deposited over the bottom solar cell; a p-doped gallium arsenic (GaAs) base layer deposited over the BSF layer; an n-doped GaAs emitter layer deposited over the base layer; and an n-doped indium gallium phosphide2 (InGaP2) window layer deposited over the emitter layer. The top solar cell includes a p-doped indium gallium aluminum phosphide (InGaA1P) back surface field (BSF) layer deposited over the middle solar cell; a p-doped GaInP2 base layer deposited over the InGaA1P BSF layer; an n-doped GaInP2 emitter layer deposited over the InGaP2 base layer; and an n-doped aluminum indium phosphide2 (AiInP2) window layer deposited over the GaInP2 emitter layer. The n-doped GaAs cap layer is deposited between the top solar cell and the lateral conduction layer. The lateral conduction layer is an n-doped GaAs layer for conducting electrical current. The p-type layer of the bypass diode is a p-doped GaAs layer. The n-type layer of the bypass diode is an n-doped GaAs layer. The i-type layer is a lightly doped GaAs layer for reducing defect breakdown, or an undoped GaAs layer for reducing defect breakdown.The solar cell structure comprises solar cell(s) disposed over the substrate; the lateral conduction layer deposited over a portion of the solar cell structure; the bypass diode deposited over the lateral conduction layer; the shunt having first and second contacting sides formed between the solar cell and the bypass diode; the well situated between the solar cell and the bypass diode, where the well provides electrical separation between the solar cell and the diode; the stop etch layer deposited over the lateral conduction layer; the first and second contact layers; and a GaAs cap layer deposited between the top sub-cell and the lateral conduction layer. The first contacting side of the shunt is connected to the substrate. The second contacting side of the shunt is connected to the lateral conduction layer. The bypass diode further includes the n-doped GaAs layer deposited over the lateral conduction layer, and the p-doped GaAs layer deposited over the n-doped GaAs layer of the bypass diode; or the p-doped GaAs layer deposited over the lateral conduction layer, and the n-doped GaAs layer deposited over the p-doped GaAs layer of the bypass diode.Preferred Method: The method further comprises depositing the stop etch layer between the lateral conduction layer and the bypass diode; depositing a first metal layer on the bypass diode for a contact pad; depositing a second metal layer on the substrate for the contact pad; and depositing the GaAs cap layer between the top sub-cell and the lateral conduction layer. The step of depositing the bypass diode further includes depositing the n-doped GaAs base layer over the stop etch layer; depositing an i-doped GaAs layer over the n-doped GaAs base layer; and depositing the p-doped GaAs emitter layer over the i-doped GaAs layer. The step of depositing the solar cell further includes depositing a Ge-type bottom sub-cell including a nucleation layer; depositing a GaAs-type middle sub-cell over the bottom sub-cell; and depositing a GaInP2-type top sub-cell over the middle sub-cell.