The present invention relates to a tandem solar cell which comprises: a perovskite solar cell comprising a perovskite absorption layer; a silicon solar cell placed under the perovskite solar cell; a junction layer placed between the perovskite solar cell and the silicon solar cell; an upper electrode placed on the perovskite solar cell; and a lower electrode placed under the silicon solar cell.

A solar cell module comprising a plurality of solar cells mounted on a flexible support, the support comprising a conductive layer on the top surface thereof divided into two electrically isolated portions—a first conductive portion and a second conductive portion. Each solar cell comprises a front surface, a rear surface, and a first contact on the rear surface and a second contact on the front surface. Each one of the plurality of solar cells is placed on the first conductive portion with the first contact electrically connected to the first conductive portion so that the solar cells are connected through the first conductive portion. A second contact of each solar cell is then connected to the second conductive portion by a respective interconnect.

A solar cell module comprising a plurality of solar cells mounted on a flexible support, the support comprising a conductive layer on the top surface thereof divided into two electrically isolated portions—a first conductive portion and a second conductive portion. Each solar cell comprises a front surface, a rear surface, and a first contact on the rear surface and a second contact on the front surface. Each one of the plurality of solar cells is placed on the first conductive portion with the first contact electrically connected to the first conductive portion so that the solar cells are connected through the first conductive portion. A second contact of each solar cell is then connected to the second conductive portion by a respective interconnect.

The invention provides an optoelectronic device comprising a photoactive region, which photoactive region comprises: an n-type region comprising at least one n-type layer; a p-type region comprising at least one p-type layer; and, disposed between the n-type region and the p-type region: a layer of a perovskite semiconductor without open porosity. The perovskite semiconductor is generally light-absorbing. In some embodiments, disposed between the n-type region and the p-type region is: (i) a first layer which comprises a scaffold material, which is typically porous, and a perovskite semiconductor, which is typically disposed in pores of the scaffold material; and (ii) a capping layer disposed on said first layer, which capping layer is said layer of a perovskite semiconductor without open porosity, wherein the perovskite semiconductor in the capping layer is in contact with the perovskite semiconductor in the first layer. The layer of the perovskite semiconductor without open porosity (which may be said capping layer) typically forms a planar heterojunction with the n-type region or the p-type region. The invention also provides processes for producing such optoelectronic devices which typically involve solution deposition or vapour deposition of the perovskite. In one embodiment, the process is a low temperature process; for instance, the entire process may be performed at a temperature or temperatures not exceeding 150° C.

The invention provides an optoelectronic device comprising a photoactive region, which photoactive region comprises: an n-type region comprising at least one n-type layer; a p-type region comprising at least one p-type layer; and, disposed between the n-type region and the p-type region: a layer of a perovskite semiconductor without open porosity. The perovskite semiconductor is generally light-absorbing. In some embodiments, disposed between the n-type region and the p-type region is: (i) a first layer which comprises a scaffold material, which is typically porous, and a perovskite semiconductor, which is typically disposed in pores of the scaffold material; and (ii) a capping layer disposed on said first layer, which capping layer is said layer of a perovskite semiconductor without open porosity, wherein the perovskite semiconductor in the capping layer is in contact with the perovskite semiconductor in the first layer. The layer of the perovskite semiconductor without open porosity (which may be said capping layer) typically forms a planar heterojunction with the n-type region or the p-type region. The invention also provides processes for producing such optoelectronic devices which typically involve solution deposition or vapour deposition of the perovskite. In one embodiment, the process is a low temperature process; for instance, the entire process may be performed at a temperature or temperatures not exceeding 150° C.

A multijunction solar cell includes an upper solar subcell, a bottom solar subcell adjacent to the upper solar subcell, a layer of light scattering elements below and directly adjacent to the bottom solar subcell, and a metallic layer disposed below and adjacent to the layer of light scattering elements.

A multijunction solar cell includes an upper solar subcell, a bottom solar subcell adjacent to the upper solar subcell, a layer of light scattering elements below and directly adjacent to the bottom solar subcell, and a metallic layer disposed below and adjacent to the layer of light scattering elements.

A photovoltaic system including an output inverter for connection to a third-party network, and at least one string, each string including at least one module of tandem photovoltaic cells, each module having a first and a second pair of connectors. The modules of a string are connected in series via their first pair of connectors. The strings are connected to the output inverter in parallel to each other via connectors of each string among the first pairs of connectors. Several modules are connected in parallel via their second pairs of connectors so as to form a first group that is coupled, via the second pairs of connectors, upstream of the output inverter, to a second group of module(s) composed of a single module or of a series of modules connected to each other in series by their first pairs of connectors.

The present disclosure relates to thin-film solar cells with improved efficiency and methods for producing thin-film solar cells having increased efficiency. In certain embodiments, thin-film solar cells having an efficiency of over 21%, over 20%, over 19%, over 15%, over 10%, etc. has been obtained using the methods of the disclosure. In certain aspects, the methods of the disclosure use passivation, passivating oxides, and/or doping treatments in increase the efficiency of the thin-film solar cells; e.g., CdTe-based thin-film solar cells.

A tandem photovoltaic device includes: an upper cell unit, a lower cell unit and a tunnel junction positioned between the upper cell unit and the lower cell unit; the tunnel junction includes an upper transport layer, a lower transport layer, and an intermediate layer positioned between the upper transport layer and the lower transport layer, the intermediate layer is an ordered defect layer, or, the intermediate layer is a continuous thin layer, or, the intermediate layer includes a first layer in contact with the lower transport layer and a second layer in contact with the upper transport layer; a doping concentration of the first layer is 10-10,000 times of a doping concentration of the lower transport layer, and the doping concentration of the first layer is less than 10.sup.21cm.sup.−3; a doping concentration of the second layer is 10-10,000 times of a doping concentration of the upper transport layer.