Disclosed are ultrathin layers of group II-VI semiconductors, group II-VI semiconductor superlattice structures, photovoltaic devices incorporating the layers and superlattice structures and related methods. The superlattice structures comprise an ultrathin layer of a first group II-VI semiconductor alternating with an ultrathin layer of at least one additional semiconductor, e.g., a second group II-VI semiconductor, or a group IV semiconductor, or a group III-V semiconductor.

Disclosed are ultrathin layers of group II-VI semiconductors, group II-VI semiconductor superlattice structures, photovoltaic devices incorporating the layers and superlattice structures and related methods. The superlattice structures comprise an ultrathin layer of a first group II-VI semiconductor alternating with an ultrathin layer of at least one additional semiconductor, e.g., a second group II-VI semiconductor, or a group IV semiconductor, or a group III-V semiconductor.

The present invention proposes a method to form a gradient thin film using a spray pyrolysis technique. The method comprises providing a base substrate, preparing a spray aqueous solution by mixing at least two precursor compounds comprising at least two different elements and spraying the spray aqueous solution onto the base substrate. According to the present invention, the ratio of the concentration of the at least two different elements within the spray aqueous solution is varied while performing the method. In this way, a thin film having a gradient of elemental composition over its layer thickness may be formed.

The present invention proposes a method to form a gradient thin film using a spray pyrolysis technique. The method comprises providing a base substrate, preparing a spray aqueous solution by mixing at least two precursor compounds comprising at least two different elements and spraying the spray aqueous solution onto the base substrate. According to the present invention, the ratio of the concentration of the at least two different elements within the spray aqueous solution is varied while performing the method. In this way, a thin film having a gradient of elemental composition over its layer thickness may be formed.

The invention relates to a photodetection device comprising a substrate and a diodes network, the substrate comprising an absorption layer (1) and each diode comprising a collection region with a first type of doping in the absorption layer (2). The device comprises a conduction mesh (7) under the surface of the substrate, comprising at least one conduction channel inserted between the collection regions (2) of two adjacent diodes, the at least one conduction channel (7) having a second doping type opposite the first type and a higher doping density than the absorption layer. The doping density of the at least one conduction channel (7) is derived from metal diffusion in the absorption layer from a metal mesh present on the substrate surface. The absorption layer has the first doping type. The invention also relates to a method of making such a device.

A photovoltaic device is disclosed including at least one Cadmium Sulfide Telluride (CdS.sub.xTe.sub.1−x) layer as are methods of forming such a photovoltaic device.

A photovoltaic device is disclosed including at least one Cadmium Sulfide Telluride (CdS.sub.xTe.sub.1−x) layer as are methods of forming such a photovoltaic device.

Topological insulators can be utilized in a new type of infrared photodetector that is intrinsically sensitive to the polarization of incident light and static magnetic fields. The detector isolates single topological insulator surfaces and allows light collection and exposure to static magnetic fields. The wavelength range of interest is between 750 nm and about 100 microns. This detector eliminates the need for external polarization selective optics. Polarization sensitive infrared photodetectors are useful for optoelectronics applications, such as light detection in environments with low visibility in the visible wavelength regime.

A photovoltaic device includes one or more features that taken alone or in combination enhance its efficiency. Some embodiments may comprise a tandem solar device in which a top PV cell is fabricated upon a front transparent substrate, that also serves as the top encapsulating substance. The top PV cell including the front encapsulating substance is then bonded (e.g., using adhesive) to a bottom PV cell in order to complete the tandem device. Using the same transparent, insulating element as both front encapsulating substance and a substrate for fabricating the top PV cell, obviates to the need to provide a separate structure (with resulting interfaces) to perform the latter role. For tandem and non-tandem PV devices, a Through-Substrate-Via (TSV) structure may extend through an insulating substrate in order to provide contact with an opposite side (e.g., back electrode). Embodiments may find particular use in fabricating shingled perovskite photovoltaic solar cells.

A photovoltaic device includes one or more features that taken alone or in combination enhance its efficiency. Some embodiments may comprise a tandem solar device in which a top PV cell is fabricated upon a front transparent substrate, that also serves as the top encapsulating substance. The top PV cell including the front encapsulating substance is then bonded (e.g., using adhesive) to a bottom PV cell in order to complete the tandem device. Using the same transparent, insulating element as both front encapsulating substance and a substrate for fabricating the top PV cell, obviates to the need to provide a separate structure (with resulting interfaces) to perform the latter role. For tandem and non-tandem PV devices, a Through-Substrate-Via (TSV) structure may extend through an insulating substrate in order to provide contact with an opposite side (e.g., back electrode). Embodiments may find particular use in fabricating shingled perovskite photovoltaic solar cells.