The disclosure relates to the technical field of solar cells, and provides a solar cell and a doped region structure thereof, a cell assembly, and a photovoltaic system. The doped region structure includes a first doped layer, a passivation layer, and a second doped layer that are disposed on a silicon substrate in sequence. The passivation layer is a porous structure having the first doped layer and/or the second doped layer inlaid in a hole region. The first doped layer and the second doped layer have a same doping polarity. By means of the doped region structure of the solar cell provided in the disclosure, the difficulty in production and the limitation on conversion efficiency as a result of precise requirements for the accuracy of a thickness of a conventional tunneling layer are resolved.

Fabrication methods and structures relating to backplanes for back contact solar cells that provide for solar cell substrate reinforcement and electrical interconnects as well as Fabrication methods and structures for forming thin film back contact solar cells are described.

Disclosed is a method of purifying a solution containing hydrofluoric acid, nitric acid and at least one silicon impurity by treating the solution with at least one reverse osmosis membrane. According to the method of the present invention, silicon impurities contained in the solution containing hydrofluoric acid and nitric acid can be selectively removed or reduced. This method can be advantageously used in the photovoltaic industry or in the battery component industry.

The present disclosure provides a structure having a low reflectance surface, wherein the structure comprises: a base plate; and a plurality of inclined rods protruding from a first face of the base plate and inclined relative to a normal line to the first face, wherein the inclined rods are spaced from each other. Travel paths of light beams in the structure may be longer along the inclined rods. As a result, a larger amount of light may be absorbed by the structure having a low reflectance surface. The amount of light-beams as reflected from the structure having a low reflectance surface may be significantly reduced.

A solar cell, and methods of fabricating said solar cell, are disclosed. The solar cell can include a substrate having a light-receiving surface and a back surface. The solar cell can include a first semiconductor region of a first conductivity type disposed on a first dielectric layer, wherein the first dielectric layer is disposed on the substrate. The solar cell can also include a second semiconductor region of a second, different, conductivity type disposed on a second dielectric layer, where a portion of the second thin dielectric layer is disposed between the first and second semiconductor regions. The solar cell can include a third dielectric layer disposed on the second semiconductor region. The solar cell can include a first conductive contact disposed over the first semiconductor region but not the third dielectric layer. The solar cell can include a second conductive contact disposed over the second semiconductor region, where the second conductive contact is disposed over the third dielectric layer and second semiconductor region. In an embodiment, the third dielectric layer can be a dopant layer.

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.

The present invention generally relates to nanoscale wires and, in particular, to nanoscale wires with heterojunctions, such as tip-localized homo- or heterojunctions. In one aspect, the nanoscale wire may include a core, an inner shell surrounding the core, and an outer shell surrounding the inner shell. The outer shell may also contact the core, e.g., at an end portion of the nanoscale wire. In some cases, such nanoscale wires may be used as electrical devices. For example a p-n junction may be created where the inner shell is electrically insulating, and the core and the outer shell are p-doped and n-doped. Other aspects of the present invention generally relate to methods of making or using such nanoscale wires, devices, or kits including such nanoscale wires, or the like.

The present invention is a method for manufacturing an FZ silicon single crystal for a solar cell, including the steps of: pulling a CZ silicon single crystal doped with gallium by a Czochralski method; and float-zone processing a raw material rod, with the raw material rod being the CZ silicon single crystal, at 1.6 atmospheric pressure or more to manufacture the FZ silicon single crystal. As a result, it is possible to provide a method for manufacturing an FZ silicon single crystal for a solar cell that can decrease the amount of gallium dopant evaporated during the float-zone processing, thereby preventing the silicon single crystal from increasing the resistance while decreasing oxygen, which is inevitably introduced into a CZ crystal, and preventing formation of a B-O pair, which causes a problem to the characteristics of a solar cell.

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).

The present invention is a method for manufacturing a substrate for a solar cell composed of a single crystal silicon, including the steps of: producing a silicon single crystal ingot; slicing a silicon substrate from the silicon single crystal ingot; and subjecting the silicon substrate to low temperature thermal treatment at a temperature of 800° C. or more and less than 1200° C., wherein the silicon single crystal ingot or the silicon substrate is subjected to high temperature thermal treatment at a temperature of 1200° C. or more for 30 seconds or more before the low temperature thermal treatment. As a result, it is possible to provide a method for manufacturing a substrate for a solar cell that can prevent decrease in the minority carrier lifetime of the substrate even when the substrate has higher oxygen concentration.