An energy conversion device comprises at least two thin film photovoltaic cells fabricated separately and joined by wafer bonding. The cells are arranged in a hierarchical stack of decreasing order of their energy bandgap from top to bottom. Each of the thin film cells has a thickness in the range from about 0.5 m to about 10 m. The photovoltaic cell stack is mounted upon a thick substrate composed of a material selected from silicon, glass, quartz, silica, alumina, ceramic, metal, graphite, and plastic. Each of the interfaces between the cells comprises a structure selected from a tunnel junction, a heterojunction, a transparent conducting oxide, and an alloying metal grid; and the top surface and/or the lower surface of the energy conversion device may contain light-trapping means.

An energy conversion device comprises at least two thin film photovoltaic cells fabricated separately and joined by wafer bonding. The cells are arranged in a hierarchical stack of decreasing order of their energy bandgap from top to bottom. Each of the thin film cells has a thickness in the range from about 0.5 m to about 10 m. The photovoltaic cell stack is mounted upon a thick substrate composed of a material selected from silicon, glass, quartz, silica, alumina, ceramic, metal, graphite, and plastic. Each of the interfaces between the cells comprises a structure selected from a tunnel junction, a heterojunction, a transparent conducting oxide, and an alloying metal grid; and the top surface and/or the lower surface of the energy conversion device may contain light-trapping means.

A p.sup. type semiconductor substrate 20 has a first principal surface 20a and a second principal surface 20b opposed to each other and includes a photosensitive region 21. The photosensitive region 21 is composed of an n.sup.+ type impurity region 23, a p.sup.+ type impurity region 25, and a region to be depleted with application of a bias voltage in the p.sup. type semiconductor substrate 20. An irregular asperity 10 is formed in the second principal surface 20b of the p.sup. type semiconductor substrate 20. An accumulation layer 37 is formed on the second principal surface 20b side of the p.sup. type semiconductor substrate 20 and a region in the accumulation layer 37 opposed to the photosensitive region 21 is optically exposed.

An optical sensor for imaging an input object, such as a fingerprint, on a sensing region of a display is disclosed. The sensor includes a transparent substrate having a first side and a second side opposite the first side. An array of detector elements is positioned above the first side of the transparent substrate and an angle limiting reflector is positioned below the second side of the transparent substrate. The angle limiting reflector is configured to reflect light incident on the angle limiting reflector within a limited acceptance angle towards the array detector elements.

Backside illuminated photosensitive devices and associated methods are provided. In one aspect, for example, a backside-illuminated photosensitive imager device can include a semiconductor substrate having multiple doped regions forming a least one junction, a textured region coupled to the semiconductor substrate and positioned to interact with electromagnetic radiation, and a passivation region positioned between the textured region and the at least one junction. The passivation region is positioned to isolate the at least one junction from the textured region, and the semiconductor substrate and the textured region are positioned such that incoming electromagnetic radiation passes through the semiconductor substrate before contacting the textured region. Additionally, the device includes an electrical transfer element coupled to the semiconductor substrate to transfer an electrical signal from the at least one junction.

A method of texturizing a silicon substrate comprising a) contacting the substrate with an etching solution comprising glycolic acid, b) etching a surface of the substrate thereby forming disruptions in said surface of the substrate, and c) removing the etching solution to yield a texturized substrate, said texturized substrate having a plurality of disruptions in at least one surface with a surface density of disruptions of a minimum of 60 disruptions in a 400 micron square area.

Embodiments of the present disclosure relates to the field of solar cells, and in particular to a solar cell and a production method thereof, and a photovoltaic module. The solar cell includes: a P-type emitter formed on a first surface of an N-type substrate and including a first portion and a second portion, a top surface of the first portion includes first pyramid structures, and a top surface of the second portion includes second pyramid structures whose edges are straight. A transition surface is respectively formed on at least one edge of each first pyramid structure, and each of top surfaces of at least a part of the first pyramid structures includes a spherical or spherical-like substructure. A tunnel layer and a doped conductive layer sequentially formed over a second surface of the N-type substrate. The present disclosure can improve the photoelectric conversion performance of solar cells.

Some embodiments of the present invention relate to a technical field of N-type TOPCon solar cells, and disclose a back-side metal electrode of an N-type TOPCon solar cell. The back-side metal electrode includes a substrate, a plurality of first silver fine grids disposed on a passivation film which is on a back side of the substrate, a plurality of second aluminum fine grids overlaid on the plurality of first silver fine grids, and a plurality of first silver main grids disposed perpendicular to the plurality of first silver fine grids. Each of the plurality of first silver main grids is a segmented structure. The back-side metal electrode further includes a plurality of second aluminum main grids, which are formed, in a printing manner, between any two adjacent grid segments of a plurality of grid segments and around each of the plurality of grid segments.

Provided is a solar cell and a photovoltaic module. The solar cell includes a silicon substrate, and the silicon substrate includes a front surface and a back surface arranged opposite to each other. P-type conductive regions and N-type conductive regions are alternately arranged on the back surface of the silicon substrate. Front surface field regions are located on the front surface of the silicon substrate and spaced from each other. The front surface field regions each corresponds to one of the P-type conductive regions or one of the N-type conductive regions. At least one front passivation layer is located on the front surface of the silicon substrate. At least one back passivation layer is located on surfaces of the P-type conductive regions and N-type conductive regions.

Methods of forming a monolayer of nanoparticles are described. The method may include forming an activated surface on a substrate. Methods may also include contacting the activated surface with a fluid including nanoparticles. Methods may further include forming a plurality of monolayers in the liquid on the activated surface. The plurality of nanoparticles may include a first monolayer of nanoparticles bonded to the activated surface. The plurality of nanoparticles may include a second monolayer of nanoparticles bonded to the first monolayer of nanoparticles. The bond strengths between a nanoparticle and the underlying substrate, between adjacent nanoparticles, and between nanoparticles of adjacent monolayers may be related by a specific relationship. The method may also include removing monolayers of the plurality of monolayers while retaining the first monolayer to form the substrate with the first monolayer. Systems for performing the methods and substrates resulting from the methods are also described.