The disclosure provides a solar cell design featuring p-or-n type GaAs with alternating p-n junction regions on the back-surface of the cell, opposite incident solar irradiance. Various layers of p-or-n type GaAs are interfaced together to collect charge carriers, and a thin layer of AlGaAs is applied to the front and back surfaces to prevent recombination of charge carriers. In some embodiments, the layered an doped structure generally provides an AlGaAs window layer of about 20 nm doped to about 4×(10.sup.18) cm.sup.−3, a GaAs absorption layer of about 2000 nm doped to about 4×(10.sup.17) cm.sup.−3, a GaAs emitter layer of about 150 nm and doped to 1×(10.sup.18) cm.sup.−3, an AlGaAs heterojunction layer of about 40 nm doped to about 3×(10.sup.18) cm.sup.−3, and a GaAs emitter-contact layer of about 20 nm doped to about 1×(10.sup.19) cm.sup.−3. Additionally, AlGaAs BSF layer and GaAs BSF-contact layers each have a depth of about 20 nm and are doped to about 4×(10.sup.18) cm.sup.−3 and 1×(10.sup.19) cm.sup.−3 respectively. The emitter layer, heterojunction layer, and emitter-contact layer are doped to a conductivity type opposite the absorption layer.

A photovoltaic device includes: a p- or n-type semiconductor substrate; a p-type amorphous semiconductor film and an n-type amorphous semiconductor film on a first-face side; p-electrodes on the p-type amorphous semiconductor film; and n-electrodes on the n-type amorphous semiconductor film, wherein: the p-electrodes and the n-electrodes are arranged at intervals; the p-type amorphous semiconductor film surrounds the n-type amorphous semiconductor film in an in-plane direction of the semiconductor substrate; the n-type amorphous semiconductor film has an edge portion providing an overlapping region where the n-type amorphous semiconductor film overlaps the p-type amorphous semiconductor film; and the n-electrodes are disposed in areas of the n-type amorphous semiconductor film that are surrounded by the overlapping region.

A solar cell having a P-type silicon substrate wherein one main surface is a light-receiving surface and another is a backside, a plurality of back surface electrodes formed on a part of the backside, an N-type layer in at least a part of the light-receiving surface, and contact areas in which the substrate contacts the electrodes; wherein the P-type silicon substrate is a silicon substrate doped with gallium and has a resistivity of 2.5 Ω.Math.cm or less; and a back surface electrode pitch P.sub.rm [mm] of the plurality of electrodes and the resistivity R.sub.sub [Ω.Math.cm] of the substrate satisfy the relation represented by the following formula (1). This provides a solar cell and a solar cell module having excellent conversion efficiency with resistance loss being prevented, with the solar cell using a substrate the light-induced degradation of which is eliminated.

log(R.sub.sub)≦−log(P.sub.m)+1.0   (1).

A high-tension busbar silver paste applied to the N-type solar cell is prepared by mixing a silver powder (a mixture of a spherical silver powder A having a median particle size of 700-900 nm and a tapped density of 5-6 g/mL and a spherical silver powder B having a medium particle size of 280-450 nm and a tapped density of 4-5 g/mL), an organic vehicle (a mixture of 3-5 wt % of polyvinyl butyral resin and 5-10 wt % of acrylic resin as a main resin) and a glass powder (copper-bismuth-manganese-tellurium series glass powder having a medium particle size of 0.7-1 μm and a softening temperature of 600-800° C.); the silver paste has large welding tension, in which the welding tension of the front busbar line is 4 N or more.

Methods of fabricating solar cell emitter regions with differentiated P-type and N-type architectures and incorporating dotted diffusion, and resulting solar cells, are described. In an example, a solar cell includes a substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region of a first conductivity type is disposed on a first thin dielectric layer disposed on the back surface of the substrate. A second polycrystalline silicon emitter region of a second, different, conductivity type is disposed on a second thin dielectric layer disposed in a plurality of non-continuous trenches in the back surface of the substrate.

The present disclosure provides a solar cell and a method for producing same. The solar cell includes: a substrate; a first passivation film, an anti-reflection layer and at least one first electrode formed on a front surface of the substrate; and a tunneling layer, a field passivation layer and at least one second electrode formed on a rear surface. The field passivation layer includes a first field passivation sub-layer and a second field passivation sub-layer; a conductivity of the first field passivation sub-layer is greater than a conductivity of the second field passivation sub-layer, and a thickness of the second field passivation sub-layer is smaller than a thickness of the first field passivation sub-layer; either the at least one first electrode or the at least one second electrode includes a silver electrode, a conductive adhesive and an electrode film that are sequentially formed in a direction away from the substrate.

An interdigitated solar cell may provide a heterojunction or tunnel junction emitter and base contacts that comprise laser processed regions that electrically couple the base contact to a substrate. Methods for manufacturing such solar cells to provide interdigitated back contacts may utilize laser processing to form laser processed regions that are isolated from the emitter. Laser processing may include laser-doping, laser-firing, laser-transfer, laser-transfer doping, laser contacting, and/or gas immersion laser doping.

After forming a doped semiconductor layer on a backside of a semiconductor substrate that has a conductivity type opposite a conductivity type of the doped semiconductor layer so as to provide a p-n junction for a photovoltaic cell, transistors are formed in a front side of the semiconductor substrate. The photovoltaic cell is then electrically connected to the transistors from the front side of the semiconductor substrate using through-dielectric (TDV) via structures embedded in the semiconductor substrate.

Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses.

Foil trim approaches for the foil-based metallization of solar cells and the resulting solar cells are described. For example, a method involves attaching a metal foil sheet to a metallized surface of an underlying supported wafer to provide a unified pairing of the metal foil sheet and the wafer. Subsequent to attaching the metal foil sheet, a portion of the metal foil sheet is laser scribed from above to form a groove in the metal foil sheet. Subsequent to laser scribing the metal foil sheet, the unified pairing of the metal foil sheet and the wafer is rotated to provide the metal sheet below the wafer. Subsequent to the rotating, the unified pairing of the metal foil sheet and the wafer is placed on a chuck with the metal sheet below the wafer. The metal foil sheet is torn at least along the groove to trim the metal foil sheet.