Patent ID: 8263856

Claim:
A method of manufacturing a solar cell comprising: providing a first substrate; depositing sequentially on the first substrate a plurality of semiconductor layers, the plurality of semiconductor layers comprising a first layer and a last layer in the direction of deposition; forming a backside contact layer on the last semiconductor layer; forming on the last semiconductor layer a back cathode contact isolated from at least a first portion of the backside contact layer, the first portion forming the anode contact; attaching a second substrate on the backside contact layer and removing the first substrate to expose the first semiconductor layer and to define a front surface and an opposite back surface of a solar cell; forming a front cathode contact on the front surface of the solar cell; etching a first trench through the plurality of semiconductor layers to define an active portion of the solar cell with a first mesa structure including the front cathode contact and the anode contact and being surrounded by the first trench, the first mesa having a first sidewall in the first trench and a lateral peripheral region beyond the sidewall, and forming in the lateral peripheral region an electrical connection between the front electrode and the back cathode contact, wherein the step of forming a back cathode contact comprises: removing a second portion of the backside contact layer to expose the last semiconductor layer in a window region; covering the window region with an electrically insulating material so as to form an electrically insulating island having a first surface area, and forming a back cathode contact on the electrically insulating island, the back cathode contact having a second surface area smaller than the first surface area so as to lie within the electrically insulating island.