A solar cell includes a semiconducting substrate, a first emitter, an insulating layer, and a second emitter. The semiconducting substrate includes a first surface and a second surface, and includes a first region and a second region. The first region includes a first sub-region and a second sub-region. The first sub-region is in contact with the second region. The first direction is perpendicular to the thickness direction of the semiconducting substrate. The first emitter is disposed on the first surface and in the first region. The insulating layer is disposed on the first emitter and in the first sub-region. The second emitter is disposed on the first surface. The second emitter includes a first sub-emitter and a second sub-emitter. The first sub-emitter is located on the second region. The second sub-emitter is disposed on the insulating layer. Electrical conduction exists between the first emitter and the first sub-emitter.

Provided is a busbar-free interdigitated back contact (IBC) solar cell and an IBC solar cell module. The IBC solar cell includes a semiconductor substrate, finger electrode lines and conductive lines. The finger electrode lines include first finger electrode lines and second finger electrode lines that are alternately arranged on the semiconductor substrate. The conductive lines include first conductive lines and second conductive lines that are alternately arranged. The first conductive lines are connected to the first finger electrode lines and spaced apart from the second finger electrode lines. The second conductive lines are connected to the second finger electrode lines and spaced apart from the first finger electrode lines.

A solar cell can include a first plurality of metal contact fingers, and a second plurality of metal contact fingers interdigitated with the first plurality of metal contact fingers, wherein at least one of the first plurality of metal contact fingers comprises a wrap-around metal finger that passes between a first edge of the solar cell and at least one contact pads. A photovoltaic (PV) string including a solar cell with a wrap-around metal contact finger. A method of coupling an electrically conductive connector to a solar cell with a wrap-around metal contact finger.

A laser processing system can be utilized to produce high-performance interdigitated back contact (IBC) solar cells. The laser processing system can be utilized to ablate, transfer material, and/or laser-dope or laser fire contacts. Laser ablation can be utilized to remove and pattern openings in a passivated or emitter layer. Laser transferring may then be utilized to transfer dopant and/or contact materials to the patterned openings, thereby forming an interdigitated finger pattern. The laser processing system may also be utilized to plate a conductive material on top of the transferred dopant or contact materials.

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. A trench structure separates the P-type doped region from the N-type doped region. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. The trench structure may include a textured surface for increased solar radiation collection. Among other advantages, the resulting structure increases efficiency by providing isolation between adjacent P-type and N-type doped regions, thereby preventing recombination in a space charge region where the doped regions would have touched.

An improved method of doping a workpiece is disclosed. The method is particularly beneficial to the creation of interdigitated back contact (IBC) solar cells. A patterned implant is performed on one surface of the workpiece. A self-aligned masking process is then performed, which is achieved by exploiting the changes in surface properties caused by the patterned implant. The masking process includes applying a coating that preferentially adheres to the previously implanted regions. A blanket implant is then performed, which serves to implant the portions of the workpiece that are not covered by the coating. Thus, the blanket implant is actually a complementary implant, doping the regions that were not implanted by the first patterned implant. The coating is then optionally removed from the workpiece.

Methods of fabricating solar cells using a metal-containing thermal and diffusion barrier layer in foil-based metallization approaches, and the resulting solar cells, are described. For example, a method of fabricating a solar cell includes forming a plurality of semiconductor regions in or above a substrate. The method also includes forming a metal-containing thermal and diffusion barrier layer above the plurality of semiconductor regions. The method also includes forming a metal seed layer on the metal-containing thermal and diffusion barrier layer. The method also includes forming a metal conductor layer on the metal seed layer. The method also includes laser welding the metal conductor layer to the metal seed layer. The metal-containing thermal and diffusion barrier layer protects the plurality of semiconductor regions during the laser welding.

An improved method of doping a workpiece is disclosed. The method is particularly beneficial to the creation of interdigitated back contact (IBC) solar cells. A patterned implant is performed on one surface of the workpiece. A self-aligned masking process is then performed, which is achieved by exploiting the changes in surface properties caused by the patterned implant. The masking process includes applying a coating that preferentially adheres to the previously implanted regions. A blanket implant is then performed, which serves to implant the portions of the workpiece that are not covered by the coating. Thus, the blanket implant is actually a complementary implant, doping the regions that were not implanted by the first patterned implant. The coating is then optionally removed from the workpiece.

A dielectric coating material system for use in a single-sided back contact solar cell is disclosed. The material system serves to electrically isolate electrodes of opposite polarity types on the same side of a silicon-based solar call, and includes titanium and phosphorus.

Passivated contact structures and fabrication methods for back contact back junction solar cells are provided. According to one example embodiment, a back contact back junction photovoltaic solar cell is described that has a semiconductor light absorbing layer having a front side and a backside having base regions and emitter regions. A passivating dielectric insulating layer is on the base and emitter regions. A first electrically conductive contact contacts the passivating dielectric insulating layer together having a work function suitable for selective collection of electrons that closely matches a conduction band of the light absorbing layer. A second electrically conductive contact contacts the passivating dielectric insulating layer together having a work function suitable for selective collection of electrons that closely matches a valence band of the light absorbing layer.