The present disclosure provides a solar cell. The solar cell includes a substrate, where the substrate has a front surface and a rear surface, the rear surface includes a textured region and a flat region, a doped surface field is formed in the textured region of the substrate; a tunneling dielectric layer, where the tunneling dielectric layer is located on the flat region; a doped conductive layer, where the doped conductive layer is located on the tunnelling dielectric layer, the doped conductive layer has doping elements, and the doped conductive layer has the same type of the doping elements with the doped surface field; a rear electrode, where a part of a bottom surface of the rear electrode is located in the doped conductive layer and the part of the bottom surface of the rear electrode is in contact with the doped surface field.

A multijunction solar cell including a substrate and a top (or light-facing) solar subcell having an emitter layer, a base layer, and a window layer adjacent to the emitter layer, the window layer composed of a material that is optically transparent, has a band gap of greater than 2.6 eV, and includes an appropriately arranged multilayer antireflection coating on the top surface thereof.

A stacked multi-junction solar cell with a back-contacted front side, having a germanium substrate that forms a rear side of the multi-junction solar cell, a germanium sub-cell and at least two III-V sub-cells, successively in the named order, and at least one passage contact opening that extends from the front side of the multi-junction solar cell through the sub-cells to the rear side and a metallic connection contact that is guided through the passage contact opening. A diameter of the passage contact opening decreases in steps from the front side to the rear side of the multi-junction solar cell. The front side of the germanium sub-cell forms a first step having a first tread depth that circumferentially projects into the passage contact opening. The second step with a second tread depth circumferentially projects into the passage contact opening.

A stacked multi-junction solar cell with a back-contacted front side, having a germanium substrate that forms a rear side of the multi-junction solar cell, a germanium sub-cell and at least two III-V sub-cells, successively in the named order, and at least one passage contact opening that extends from the front side of the multi-junction solar cell through the sub-cells to the rear side and a metallic connection contact that is guided through the passage contact opening. A diameter of the passage contact opening decreases in steps from the front side to the rear side of the multi-junction solar cell. The front side of the germanium sub-cell forms a first step having a first tread depth that circumferentially projects into the passage contact opening. The second step with a second tread depth circumferentially projects into the passage contact opening.

The present disclosure provides a solar cell. The solar cell includes a substrate, where the substrate has a front surface and a rear surface, the rear surface includes a textured region and a flat region, a doped surface field is formed in the textured region of the substrate; a tunneling dielectric layer, where the tunneling dielectric layer is located on the flat region; a doped conductive layer, where the doped conductive layer is located on the tunnelling dielectric layer, the doped conductive layer has doping elements, and the doped conductive layer has the same type of the doping elements with the doped surface field; a rear electrode, where a part of a bottom surface of the rear electrode is located in the doped conductive layer and the part of the bottom surface of the rear electrode is in contact with the doped surface field.

The present invention refers to a three terminal tandem solar generation unit (1) comprising: —a first absorbing layer (7) made of a perovskite type compound, —a second absorbing layer (11, 11′), —a first and a second interdigitated front contacts (5a, 5b) arranged on the front side of the first absorbing layer (7), the first front contact (5a) having a first polarity and the second front contact (5b) having a second polarity, —a back contact (17, 17′) having the first or the second polarity arranged on the back side of the second absorbing layer (11, 11′), —an interface layer (9, 90, 9′, 90′) arranged between the first (7) and the second (11, 11′) absorbing layers comprising a first semiconductor sub-layer (9a, 90a, 9a′, 90a′) doped according to the first polarity and a second sub-layer (9b, 90b, 9b′, 90b′) doped according to the second polarity and configured for enabling carriers associated with a polarity different than the polarity of the back contact (17, 17′) to be transferred from the second absorbing layer (11, 11′) to the first absorbing layer (7) to be collected by the front contact (5a, 5b) having a polarity different than the polarity of the back contact (17, 17′).

The present invention refers to a three terminal tandem solar generation unit (1) comprising: —a first absorbing layer (7) made of a perovskite type compound, —a second absorbing layer (11, 11′), —a first and a second interdigitated front contacts (5a, 5b) arranged on the front side of the first absorbing layer (7), the first front contact (5a) having a first polarity and the second front contact (5b) having a second polarity, —a back contact (17, 17′) having the first or the second polarity arranged on the back side of the second absorbing layer (11, 11′), —an interface layer (9, 90, 9′, 90′) arranged between the first (7) and the second (11, 11′) absorbing layers comprising a first semiconductor sub-layer (9a, 90a, 9a′, 90a′) doped according to the first polarity and a second sub-layer (9b, 90b, 9b′, 90b′) doped according to the second polarity and configured for enabling carriers associated with a polarity different than the polarity of the back contact (17, 17′) to be transferred from the second absorbing layer (11, 11′) to the first absorbing layer (7) to be collected by the front contact (5a, 5b) having a polarity different than the polarity of the back contact (17, 17′).

A tandem cell and a manufacturing method thereof are provided in the present disclosure, so as to improve hole transmission performance of the tandem cell. The tandem cell includes a bottom cell, a hole transporting layer formed on the bottom cell, a perovskite absorbing layer formed on the hole transporting layer, and a transparent conducting layer formed above the perovskite absorbing layer. A material of the hole transporting layer includes a semiconductor material with a p-type delafossite structure, and a valence band top energy level of the hole transporting layer sequentially decreases in a direction away from the bottom cell, which has dual functions of carrier transport and carrier recombination, so as to simplify a cell structure and optimize the photoelectric conversion efficiency. The tandem cell and the manufacturing method thereof according to the present disclosure are used for manufacturing the tandem cell.

A method for manufacturing a stacked thin film, includes forming a photoelectric conversion layer on a first transparent electrode by sputtering using a target mainly composed of copper in an oxygen containing atmosphere. An oxygen partial pressure of the sputtering is in a range of 0.01 [Pa] or more and 4.8 [Pa] or less, and 0.24×d [Pa] or more and 2.4×d [Pa] or less when a deposition rate is d [μm/min], in formation of the photoelectric conversion layer. A sputtering temperature is 300° C. or more and 600° C. or less, in formation of the photoelectric conversion layer.

A multijunction solar cell including an upper first solar subcell having an emitter and base layers forming a photoelectric junction; a second solar subcell disposed under and adjacent to the upper first solar subcell, and having an emitter and base layers forming a photoelectric junction; and a third solar subcell disposed under and adjacent to the second solar subcell and having an emitter and base layers forming a photoelectric junction; wherein at least one of the base and emitter layers of at least a particular solar subcell from among the upper first solar subcell, the second solar subcell, and the third solar subcell has a graded band gap throughout at least a portion of thickness of its active layer adjacent to the photoelectric junction and being in a range of 20 to 300 MeV greater than a band gap in the active layer away from the photoelectric junction.