A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

A photovoltaic cell array and a photovoltaic module are provided. The photovoltaic cell array includes multiple solar cells and a flexible metal conductive strip. Each solar cell includes an upper surface, upper segment electrodes, a lower surface, and lower segment electrodes. A first solar cell including a first overlap region is adjacent to a second solar cell including a second overlap region. The second overlap region, a third overlap region of the flexible metal conductive strip, and the first overlap region are sequentially stacked. The flexible metal conductive strip is welded to only one lower segment electrode and only one upper segment electrode. The lower segment electrodes of the first solar cell are outside the first overlap region, and the upper segment electrodes are outside the second overlap region.

The present disclosure discloses a solar module, including solar cells and electrode lines. Each of the solar cells includes a solar cell substrate and a plurality of busbars located on one side of the solar cell substrate. Each of the electrode lines has one end connected to the busbar on a front surface of one solar cell, and the other end connected to the busbar on a rear surface of another solar cell adjacent to the one cell sheet. First electrode pads are provided at each busbar, a number of the first electrode pads ranges from 6 to 12. A relation between a diameter of the electrode line and a number of busbars is 2.987x.sup.-1.144-1.9<y<3.2742x.sup.-1.134+1.7, where x denotes the diameter of the electrode line, and y denotes the number of busbars.

A back contact structure of a solar cell, includes: a silicon substrate, the silicon substrate including a back surface including a plurality of recesses disposed at intervals; a plurality of first conductive regions and a plurality of second conductive regions disposed alternately in the plurality of recesses, where each first conductive region includes a first dielectric layer and a first doped region which are disposed successively in the plurality of recesses, and each second conductive region includes a second doped region; a second dielectric layer disposed between the plurality of first conductive regions and the plurality of second conductive regions; and a conductive layer disposed on the plurality of first conductive regions and the plurality of second conductive regions.

A solar cell is provided with: a semiconductor substrate having a light-receiving surface and a non-light-receiving surface; a PN junction section formed on the semiconductor substrate; a passivation layer formed on the light-receiving surface and/or the non-light-receiving surface; and power extraction electrodes formed on the light-receiving surface and the non-light-receiving surface. The solar cell is characterized in that the passivation layer includes an aluminum oxide film having a thickness of 40 nm or less. As a result of forming a aluminum oxide film having a predetermined thickness on the surface of the substrate, it is possible to achieve excellent passivation performance and excellent electrical contact between silicon and the electrode by merely firing the conductive paste, which is conventional technology. Furthermore, an annealing step, which has been necessary to achieve the passivation effects of the aluminum oxide film in the past, can be eliminated, thus dramatically reducing costs.

A solar cell is provided with: a semiconductor substrate having a light-receiving surface and a non-light-receiving surface; a PN junction section formed on the semiconductor substrate; a passivation layer formed on the light-receiving surface and/or the non-light-receiving surface; and power extraction electrodes formed on the light-receiving surface and the non-light-receiving surface. The solar cell is characterized in that the passivation layer includes an aluminum oxide film having a thickness of 40 nm or less. As a result of forming a aluminum oxide film having a predetermined thickness on the surface of the substrate, it is possible to achieve excellent passivation performance and excellent electrical contact between silicon and the electrode by merely firing the conductive paste, which is conventional technology. Furthermore, an annealing step, which has been necessary to achieve the passivation effects of the aluminum oxide film in the past, can be eliminated, thus dramatically reducing costs.

A bifacial solar cell includes a silicon substrate; an emitter layer; a plurality of first electrodes locally on the emitter layer; a first aluminum oxide layer on the emitter layer; a first silicon oxide layer between the first aluminum oxide layer and the emitter layer; a first anti-reflection layer on the first aluminum oxide layer; a back surface field layer on the silicon substrate; a second aluminum oxide layer on the silicon substrate; a second silicon oxide layer between the second aluminum oxide layer and the silicon substrate; a second anti-reflection layer on the second aluminum oxide layer; and a plurality of second electrodes respectively on the back surface field layers through the second anti-reflection layer, the second aluminum oxide layer and the second silicon oxide layer.

A bifacial solar cell includes a silicon substrate; an emitter layer; a plurality of first electrodes locally on the emitter layer; a first aluminum oxide layer on the emitter layer; a first silicon oxide layer between the first aluminum oxide layer and the emitter layer; a first anti-reflection layer on the first aluminum oxide layer; a back surface field layer on the silicon substrate; a second aluminum oxide layer on the silicon substrate; a second silicon oxide layer between the second aluminum oxide layer and the silicon substrate; a second anti-reflection layer on the second aluminum oxide layer; and a plurality of second electrodes respectively on the back surface field layers through the second anti-reflection layer, the second aluminum oxide layer and the second silicon oxide layer.

A solar cell module is discussed. The solar cell module includes a plurality of solar cells each including a semiconductor substrate and a plurality of first electrodes and a plurality of second electrodes, which are formed on a back surface of the semiconductor substrate and are separated from each other, the plurality of solar cells disposed in a first direction; a plurality of first conductive lines connected to the plurality of first electrodes included in a first solar cell of the plurality of solar cells, and the plurality of first conductive lines extended in the first direction; a plurality of second conductive lines connected to the plurality of second electrodes included in a second solar cell of the plurality of solar cells which is adjacent to the first solar cell, and the plurality of second conductive lines extended in the first direction.

The present invention provides a method for manufacturing a solar cell including: preparing a semiconductor silicon substrate which has an electrode, which is formed by baking an electrode precursor containing Ag powder on at least one main surface, has a PN junction, and is less than 100° C.; and performing an annealing treatment to the semiconductor silicon substrate at 100° C. or more and 450° C. or less. Consequently, there is provided the method for manufacturing a solar cell which suppresses a degradation phenomenon that an output of the solar cell is lowered when the solar cell is left as it stands at a room temperature in the atmosphere.