A stacked monolithic multijunction solar cell, which includes a first subcell having a p-n junction with an emitter layer and a base layer, the thickness of the emitter layer being less than the thickness of the base layer at least by a factor of ten, and the first subcell comprising a substrate having a semiconductor material from the groups III and V or a substrate from the group IV, and which further includes a second subcell arranged on the first subcell and a third subcell arranged on the second subcell, the two subcells each including an emitter layer and a base layer, and a tunnel diode and a back side field layer each being formed between the subcells, the thickness of the emitter layer being greater than the thickness of the base layer in each case between the second subcell and in the third subcell.

A back contact solar cell string includes: at least two cell pieces, where each cell piece comprises positive electrode regions and negative electrode regions alternately disposed with each other; insulation layers, covering the positive electrode regions on one side of the cell piece and the negative electrode regions on another side of the cell piece; and a first bus bar, connected to two adjacent cell pieces and electrically connected to the positive electrode regions and the negative electrode regions in the two adjacent cell pieces that are not covered by the insulation layers.

A method for soldering a solar cell, includes: placing a plurality of back contact cells on a soldering platform, where back surfaces of the back contact cells face away from the soldering platform, and electrodes corresponding to two adjacent back contact cells have opposite polarities in a connection direction of a plurality of to-be-connected ribbons; placing the plurality of to-be-connected ribbons on the electrodes of the plurality of back contact cells by using a first clamping portion, a second clamping portion, and a plurality of third clamping portions, where the first clamping portion, the second clamping portion, and the plurality of third clamping portions respectively correspond to head ends, tail ends, and middle portions of the plurality of ribbons; and heating the plurality of ribbons by using a heater to connect the plurality of ribbons to the plurality of back contact cells.

A solar module and a method for fabricating a solar module comprising a plurality of rear contact solar cells are described. Rear contact solar cells (1) are provided with a large size of e.g. 156×156 mm.sup.2. Soldering pad arrangements (13, 15) applied on emitter contacts (5) and base contacts (7) are provided with one or more soldering pads (9, 11) arranged linearly. The soldering pad arrangements (13, 15) are arranged asymmetrically with respect to a longitudinal axis (17). Each solar cell (1) is then separated into first and second cell portions (19, 21) along a line (23) perpendicular to the longitudinal axis (17). Due to such cell separation and the asymmetrical design of the soldering pad arrangements (13, 15), the first and second cell portions (19, 21) may then be arranged alternately along a line with each second cell portion (21) arranged in a 180°-orientation with respect to the first cell portions (19) and such that emitter soldering pad arrangements (13) of a first cell portion (19) are aligned with base soldering pad arrangements (15) of neighboring second cell portions (21), and vice versa. Simple linear ribbon-type connector strips (25) may be used for interconnecting the cell portions (19, 21) by soldering onto the underlying aligned emitter and base soldering pad arrangements (13, 15). The interconnection approach enables using standard ribbon-type connector strips (25) while reducing any bow as well as reducing series resistance losses.

A preparation method of a low-cost passivated contact full-back electrode solar cell includes: performing alkali polishing on a Si wafer; performing RCA cleaning and HF cleaning; growing a tunnel SiO.sub.x film layer, an in-situ doped amorphous Si film layer, and a texturing mask layer on the back of the Si wafer; performing annealing activation on the amorphous Si film layer to form a polycrystalline Si film layer; etching the texturing mask layer; performing double-sided texturing on the Si wafer; performing HF cleaning to remove the texturing mask layer; depositing an AlO.sub.x film on the front and back of the Si wafer; depositing a SiN.sub.x passivation film on the front and back of the Si wafer; ablating a part of the AlO.sub.x film and a part of the SiN.sub.x passivation film on the back of the Si wafer; and performing screen-printing and sintering on the back of the Si wafer.

A photovoltaic module and a method for manufacturing the photovoltaic module are provided. The photovoltaic module includes a battery module including multiple cell string groups and multiple first connection structures. Each cell string group includes multiple cell strings arranged along a first direction. Each cell string includes multiple solar cells and multiple second connection structures. Each solar cell includes multiple first grid lines and multiple second grid lines. There is a distance L between a first grid line and a second grid line adjacent to the first grid line in the first direction. A second connection structure connected to an end of a respective middle first connection structure is spaced apart by a distance S in the first direction from an adjacent second connection structure connected to an end of another middle first connection structure adjacent to the respective middle first connection structure and the distance S is greater than the distance L.

A back contact structure includes: a silicon substrate including a back surface including a plurality of recesses disposed at intervals; a plurality of first conductive regions and a plurality of second conductive regions disposed alternately on the back surface of the silicon substrate; a second dielectric layer disposed between the plurality of first conductive regions and the plurality of second conductive regions; and a conductive layer disposed on the plurality of first conductive regions and the plurality of second conductive regions. One of the plurality of first conductive regions and the plurality of second conductive regions is disposed inside the plurality of recesses, respectively, and the other one is disposed outside the plurality of recesses; each first conductive region includes a first dielectric layer and a first doped region which are disposed successively, and each second conductive region includes a second doped region.

The present disclosure relates to the technical field of solar cells, and relates to a crystalline silicon solar cell and a preparation method thereof, and a photovoltaic assembly. The crystalline silicon solar cell includes a crystalline silicon substrate, a passivation layer that is disposed on the crystalline silicon substrate and that is provided with through holes, a carrier collection layer that is disposed on the passivation layer, and electrodes that contact the carrier collection layer; the carrier collection layer contacts the crystalline silicon substrate by means of the through holes on the passivation layer. In the described crystalline silicon solar cell, through holes are provided on the passivation layer, and the carrier collection layer contacts the crystalline silicon substrate by means of the through holes on the passivation layer.

A solar cell (1) includes a semiconductor substrate (10) having a light-receiving surface (10a) and a back surface (10b); an n-type semiconductor layer (13n) and a p-type semiconductor layer (12p) provided on the back surface (10b) of the semiconductor substrate (10), the n-type semiconductor layer (13n) and the p-type semiconductor layer (12p) extending in a first direction and being adjacent to each other in a second direction intersecting with the first direction; and a ground layer (14) provided on the n-type semiconductor layer (13n) and the p-type semiconductor layer (12p). The ground layer (14) includes an n-side ground layer (14n) and a p-side ground layer (14p) separated from each other by a first separating groove (17) having a first separating portion (17a) and a second separating portion (17b) as well as a first bridge portion (18) separating the first separating portion (17a) and the second separating portion (17b). The first bridge portion (18) separates the first separating portion (17a) and the second separating portion (17b) at at least one of a border on the n-side ground layer (14n) or a border on the p-side ground layer (14p) in the first direction.

A solar module and a method for fabricating a solar module comprising a plurality of rear contact solar cells are described. Rear contact solar cells (1) are provided with a large size of e.g. 156×156 mm.sup.2. Soldering pad arrangements (13, 15) applied on emitter contacts (5) and base contacts (7) are provided with one or more soldering pads (9, 11) arranged linearly. The soldering pad arrangements (13, 15) are arranged asymmetrically with respect to a longitudinal axis (17). Each solar cell (1) is then separated into first and second cell portions (19, 21) along a line (23) perpendicular to the longitudinal axis (17). Due to such cell separation and the asymmetrical design of the soldering pad arrangements (13, 15), the first and second cell portions (19, 21) may then be arranged alternately along a line with each second cell portion (21) arranged in a 180°-orientation with respect to the first cell portions (19) and such that emitter soldering pad arrangements (13) of a first cell portion (19) are aligned with base soldering pad arrangements (15) of neighboring second cell portions (21), and vice versa. Simple linear ribbon-type connector strips (25) may be used for interconnecting the cell portions (19, 21) by soldering onto the underlying aligned emitter and base soldering pad arrangements (13, 15). The interconnection approach enables using standard ribbon-type connector strips (25) while reducing any bow as well as reducing series resistance losses.