A method of manufacturing an all back contact solar cell which has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. A second emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The method further includes forming contact holes that allow metal contacts to connect to corresponding emitters.

Disclosed is a preparation method of a polycrystalline silicon ingot. The preparation method comprises: providing a silicon nucleation layer at the bottom of a crucible, and filling a silicon material above the silicon nucleation layer; heating the silicon material to melt same, adjusting the thermal field inside the crucible to make the melted silicon material to start crystallization on the basis of the silicon nucleation layer; and when the crystallization is finished, performing annealing and cooling to obtain a polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot. Further disclosed are a polycrystalline silicon ingot obtained through the preparation method and a polycrystalline silicon wafer made using the polycrystalline silicon ingot as a raw material.

A bipolar solar cell includes a backside junction formed by a silicon substrate and a first doped layer of a first dopant type on the backside of the solar cell. A second doped layer of a second dopant type makes an electrical connection to the substrate from the front side of the solar cell. A first metal contact of a first electrical polarity electrically connects to the first doped layer on the backside of the solar cell, and a second metal contact of a second electrical polarity electrically connects to the second doped layer on the front side of the solar cell. An external electrical circuit may be electrically connected to the first and second metal contacts to be powered by the solar cell.

Methods of fabricating solar cell emitter regions using silicon nano-particles and the resulting solar cells are described. In an example, a method of fabricating an emitter region of a solar cell includes forming a region of doped silicon nano-particles above a dielectric layer disposed above a surface of a substrate of the solar cell. A layer of silicon is formed on the region of doped silicon nano-particles. At least a portion of the layer of silicon is mixed with at least a portion of the region of doped silicon nano-particles to form a doped polycrystalline silicon layer disposed on the dielectric layer.

Described herein are methods of fabricating solar cells. In an example, a method of fabricating a solar cell includes forming an amorphous dielectric layer on the back surface of a substrate opposite a light-receiving surface of the substrate. The method also includes forming a microcrystalline silicon layer on the amorphous dielectric layer by plasma enhanced chemical vapor deposition (PECVD). The method also includes forming an amorphous silicon layer on the microcrystalline silicon layer by PECVD. The method also includes annealing the microcrystalline silicon layer and the amorphous silicon layer to form a homogeneous polycrystalline silicon layer from the microcrystalline silicon layer and the amorphous silicon layer. The method also includes forming an emitter region from the homogeneous polycrystalline silicon layer.

Methods of fabricating solar cells using simplified deposition processes, and the resulting solar cells, are described. In an example, a method of fabricating a solar cell involves loading a template substrate into a deposition chamber and, without removing the template substrate from the deposition chamber, performing a deposition method. The deposition method involves forming a first silicon layer on the template substrate, the first silicon layer of a first conductivity type. The deposition method also involves forming a second silicon layer on the first silicon layer, the second silicon layer of the first conductivity type. The deposition method also involves forming a third silicon layer above the second silicon layer, the third silicon layer of a second conductivity type. The deposition method also involves forming a solid state doping layer on the third silicon layer, the solid state doping layer of the first conductivity type.

The invention relates to a photoactive semiconductor component, especially a photovoltaic solar cell, having a semiconductor substrate, a carbon-containing SiC layer disposed indirectly upon a surface of the semiconductor substrate, and a passivating intermediate layer disposed indirectly or directly between the SiC layer and semiconductor substrate, and a metallic contact connection disposed indirectly or directly upon a side of the SiC layer facing away from the passivating intermediate layer and in electrically conductive connection with the SiC layer, where the SiC layer has p-type or n-type doping, which is characterized in that the SiC layer partly has a partly amorphous structure and partly has a crystalline structure.

A back-contact Si thin-film solar cell includes a crystalline Si absorber layer and an emitter layer arranged on the crystalline Si absorber layer, which include a contact system being arranged on the back so as to collect excess charge carriers generated by the incidence of light in the absorber layer; a barrier layer having a layer thickness in a range of from 50 nm to 1 m formed on a glass substrate; at least one coating layer intended for optical coating and thin layer containing silicon and/or oxygen adjoining the crystalline Si absorber layer arranged on the at least one coating layer for improving the optical characteristics. The crystalline Si absorber layer can be produced by means of liquid-phase crystallization, is n-conducting, and has monocrystalline Si grains. An SiO2 passivation layer is formed between the layer containing silicon and/or oxygen and the Si absorber layer during the liquid-phase crystallization.

Casting polycrystalline silicon includes placing a bottomless cooling crucible divided at least partially in the axis direction into a plurality of parts in the peripheral direction and having an inner surface coated with a release agent containing nitrogen, in an induction coil of a chamber charged with an inert gas; melting a raw material of polycrystalline silicon in the bottomless cooling crucible by electromagnetic induction heating using the induction coil; and pulling out the molten silicon downward while cooling and solidifying it. Pullout of the solidified molten silicon is performed through adjusting the carbon concentration of the molten silicon to 4.010.sup.17 atoms/cm.sup.3 or more to 6.010.sup.17 atoms/cm.sup.3 or less, the oxygen concentration thereof to 0.310.sup.17 atoms/cm.sup.3 or more to 5.010.sup.17 atoms/cm.sup.3 or less, and the nitrogen concentration to 8.010.sup.13 atoms/cm.sup.3 or more to 1.010.sup.18 atoms/cm.sup.3 or less.

A method for manufacturing high efficiency solar cells is disclosed. The method comprises providing a thin dielectric layer and a doped polysilicon layer on the back side of a silicon substrate. Subsequently, a high quality oxide layer and a wide band gap doped semiconductor layer can both be formed on the back and front sides of the silicon substrate. A metallization process to plate metal fingers onto the doped polysilicon layer through contact openings can then be performed. The plated metal fingers can form a first metal gridline. A second metal gridline can be formed by directly plating metal to an emitter region on the back side of the silicon substrate, eliminating the need for contact openings for the second metal gridline. Among the advantages, the method for manufacture provides decreased thermal processes, decreased etching steps, increased efficiency and a simplified procedure for the manufacture of high efficiency solar cells.