A solid-state device includes a substrate with a stack of constituent thin-film layers that define an arrangement of electrodes and intervening layers. The constituent layers can conform to or follow a non-planar surface of the substrate, thereby providing a 3-D non-planar geometry to the stack. Fabrication employs a common shadow mask moved between lateral positions offset from each other to sequentially form at least some of the layers in the stack, whereby layers with a similar function (e.g., anode, cathode, etc.) can be electrically connected together at respective edge regions. Wiring layers can be coupled to the edge regions for making electrical connection to the respective subset of layers, thereby simplifying the fabrication process. By appropriate selection and deposition of the constituent layers, the multi-layer device can be configured as an energy storage device, an electro-optic device, a sensing device, or any other solid-state device.

A flexible ultraviolet sensor circuit is provided comprising a number of solar cells, a reflective display device electrically connected to the solar cells, and a floating gate transistor electrically connected to the solar cells and reflective display device. A floating gate in the floating gate transistor discharges in response to ultraviolet light such that the floating gate transistor turns on when a threshold voltage of the floating gate transistor drops below a combined open circuit voltage of the solar cells minus a switching threshold of the reflective display device, thereby causing electrical current flow through the ultraviolet sensor circuit. The reflective display device changes as the electrical current flow increases, indicating total ultraviolet light exposure.

A modular photovoltaic system adapted for collecting light rays from a solar light source to generate electrical current, the system having a light-tracking solar collector adapted to collect the light rays, an edge-lit photovoltaic array, and a transport conduit adapted to transport the light rays to the edge-lit photovoltaic array. The edge-lit photovoltaic array has a plurality of edge-lit photovoltaic panels, each having a transparent diffusing pane positioned between two backing panels with inwardly directed photovoltaic surfaces. Each edge-lit photovoltaic panel perpendicularly contacts a lateral light distributor attached to the transport conduit, causing the transparent diffusing pane to illuminate the photovoltaic surfaces to generate electrical current. The light-tracking solar collector is adapted to rotate to remain oriented toward the solar light source.

A modular photovoltaic system adapted for collecting light rays from a solar light source to generate electrical current, the system having a light-tracking solar collector adapted to collect the light rays, an edge-lit photovoltaic array, and a transport conduit adapted to transport the light rays to the edge-lit photovoltaic array. The edge-lit photovoltaic array has a plurality of edge-lit photovoltaic panels, each having a transparent diffusing pane positioned between two backing panels with inwardly directed photovoltaic surfaces. Each edge-lit photovoltaic panel perpendicularly contacts a lateral light distributor attached to the transport conduit, causing the transparent diffusing pane to illuminate the photovoltaic surfaces to generate electrical current. The light-tracking solar collector is adapted to rotate to remain oriented toward the solar light source.

Photovoltaic cells, photovoltaic devices, and methods of fabrication are provided. The photovoltaic cells include a transparent substrate to allow light to enter the photovoltaic cell through the substrate, and a light absorption layer associated with the substrate. The light absorption layer has opposite first and second surfaces, with the first surface being closer to the transparent substrate than the second surface. A passivation layer is disposed over the second surface of the light absorption layer, and a plurality of first discrete contacts and a plurality of second discrete contacts are provided within the passivation layer to facilitate electrical coupling to the light absorption layer. A first electrode and a second electrode are disposed over the passivation layer to contact the plurality of first discrete contacts and the plurality of second discrete contacts, respectively. The first and second electrodes include a photon-reflective material.

Methods are provided for fabricating photovoltaic cell contacts, which include: providing a block copolymer layer above an electrical contact layer of the photovoltaic cell, the block copolymer layer being self-assembled by phase segregation to include multiple structures of a first polymer material surrounded, at least in part, by a second polymer material; selectively etching the block copolymer layer to remove the multiple structures, forming holes in the block copolymer layer; and using the holes in the block copolymer layer to facilitate providing electrical contacts between a light absorption layer of the photovoltaic cell and the electrical contact layer. For instance, the holes in the copolymer layer may be used in etching a passivation layer over the electrical contact layer to form nano-sized contact openings in the passivation layer to the contact layer. Once provided, the cell's light absorption material forms contacts extending through the contact openings in the passivation layer.

A method for thermal exfoliation includes providing a target layer on a substrate to form a structure. A stressor layer is deposited on the target layer. The structure is placed in a temperature controlled environment to induce differential thermal expansion between the target layer and the substrate. The target layer is exfoliated from the substrate when a critical temperature is achieved such that the target layer is separated from the substrate to produce a standalone, thin film device.

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including CuZnSnS(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

A PV module includes a transparent substrate, a first solar cell unit, a crystalline silicon solar cell, and a spacer. The first solar cell unit is between the transparent substrate and the crystalline silicon solar cell, and the first solar cell unit includes a first electrode, a second electrode, and a I-III-VI semiconductor layer between the first electrode and the second electrode. The I-III-VI semiconductor layer includes at least gallium (Ga) and sulfur (S), and the energy gap thereof is more than that of crystalline silicon. Moreover, the crystalline silicon solar cell and the first solar cell unit are separated by the spacer.

An interconnect assembly. The interconnect assembly includes a trace that includes a plurality of electrically conductive portions. The plurality of electrically conductive portions is configured both to collect current from a first solar cell and to interconnect electrically to a second solar cell. In addition, the plurality of electrically conductive portions is configured such that solar-cell efficiency is substantially undiminished in an event that any one of the plurality of electrically conductive portions is conductively impaired.