METHOD FOR REPAIRING SOLAR CELL MODULE

A method for repairing a solar cell module includes the following steps. A solar cell module, which is provided, includes a first and a second solar cell serially connected. A first terminal is electrically connected to a first electrode layer of the first solar cell. A second terminal is electrically connected to a second electrode layer of the second solar cell. A polarity of the first electrode layer is the same as that of the second electrode layer. A biased voltage signal is generated and transmitted to the first solar cell and the second solar cell through the first terminal and the second terminal. The biased voltage signal includes a forward biased voltage part greater than zero and a reversed biased voltage part smaller than zero. The voltage value of the reversed biased voltage part is increasingly decreased in a step-like manner as time goes by.

DETAILED DESCRIPTION

FIG. 3is a schematic view of a device for repairing a solar cell module according to an embodiment of the present disclosure. The device200is adapted to repair a solar cell module. For ease of description, in this embodiment, a solar cell module300ofFIG. 3serves as a repaired module, so as to give a detailed description of the device200for repairing the solar cell module.

The solar cell module300has a plurality of solar cells300′. The solar cell300′ comprises a substrate310, a TCO layer320, a photovoltaic conversion layer330, and a back electrode layer340. The TCO layer320, the photovoltaic layer330, and the back electrode layer340are stacked on the substrate310in sequence. A material of the substrate310is, for example, glass or resin, so that the substrate310has excellent insulativity. A material of the transparent electrode layer320is, for example, indium tin oxide (ITO), ZnO, SnO2, or other transparent conductive materials. A material of the photovoltaic layer330is, for example, an amorphous silicon-based semiconductor or a GaAs-based material. A material of the back electrode layer340may be silver, ZnO, or other conductive materials. It should be noted that, positions of the TCO layer320and the back electrode layer340are not used to limit the types of the cells applicable to the device200for repairing the solar cell module of the present disclosure. In other embodiments of the present disclosure, the back electrode layer340of the repaired solar cell300′ may contact the substrate310, and the photovoltaic layer330is located between the transparent electrode layer320and the back electrode layer340.

In the solar cell module300of this embodiment, one solar cell300′ is serially connected to another adjacent solar cell300′ through a conductive post342. More particularly, the back electrode layer340of one solar cell300′ is electrically connected to the back electrode layer of another adjacent solar cell300′ through the conductive post342.

The device200for repairing the solar cell module comprises a first terminal210, a second terminal220, and a power supply device230. The first terminal210is electrically connected to the back electrode layer340of one solar cell300′. The second terminal220is electrically connected to the back electrode layer340of another solar cell300′. In this embodiment, multiple other solar cells300′ are serially connected between the two solar cells300′ electrically connected to the first terminal210and the second terminal220. However, in other embodiments of the present disclosure, the two solar cells300′ respectively electrically connected to the first terminal210and the second terminal220may be directly serially connected to each other, that is, no additional solar cells300′ are not serially connected between the two solar cells300′.

The power supply device230is electrically connected between the first terminal210and the second terminal220. The power supply device230is, for example, a pulse generator or a DC power generator, and is used to generate a biased voltage signal.FIG. 4is a schematic view of a biased voltage signal S output from the power supply device230inFIG. 3. After the first terminal210and the second terminal220are electrically connected to the two corresponding back electrode layers340, and after the power supply device230generates the biased voltage signal S, the biased voltage signal S is transmitted to the solar cells300′ electrically connected to the first terminal210and the second terminal220through the first terminal210and the second terminal220.

The biased voltage signal S has a forward biased voltage part I and a reversed biased voltage part II. In this embodiment, the photovoltaic layer330is formed by stacking a P-type semiconductor layer, an intrinsic semiconductor layer, and an N-type semiconductor layer. For a definition of the forward biased voltage part I, in an external voltage applied to the solar cell300′, the voltage flowing from the P-type semiconductor layer to the N-type semiconductor layer internally forms the forward biased voltage, and for a definition of the reversed biased voltage part II, in the external voltage applied to the solar cell300′, the voltage flowing from the N-type semiconductor layer to the P-type semiconductor layer internally forms the reversed biased voltage.

The reversed biased voltage part II has multiple voltage bands R arranged by time. A voltage value of each voltage band R is a fixed value, and the voltage value (being a negative number) of any voltage band in the reversed biased voltage part II is greater than a breakdown voltage value VB(being a negative number) of the solar cells300′. The voltage value of the earlier-generated voltage band R is greater than the voltage value of the later-generated voltage band R. In other words, a waveform of the reversed biased voltage part II of this embodiment is in a step-like shape, and the voltage value of the step-like reversed biased voltage part II is increasingly decreased as time goes by. In addition, a duration of the reversed biased voltage part II is longer than that of the forward biased voltage part I. In this embodiment, the forward biased voltage part I is a fixed value, and the voltage value of the forward biased voltage part I is smaller than an open circuit voltage value VOCof the solar cells300′.

Based on the above structure, the waveform of the reversed biased voltage part II in this embodiment is in a step-like shape, such that under a unit time and a fixed voltage drop, the step-like waveform of the reversed biased voltage of this embodiment may provide relatively more energy to the semiconductor crystals or residual thin films150that are not completely removed (referring toFIG. 2), so as to oxidize the semiconductor crystals or the residual thin films150. After the semiconductor crystals150or the residual thin films are oxidized, the forward biased voltage part I after the reversed biased voltage part II may be further applied to eliminate electrons and holes accumulated in the solar cells300′, which are generated during the process of removing (oxidizing) the semiconductor crystals150or the residual thin films.

It should be noted that, in the above embodiment, although a pair of the first terminal210and the second terminal220are used to respectively electrically contact the back electrode layers340of a pair of solar cells300′, this embodiment is not intended to limit the number of the first terminal210and the second terminal220in the present disclosure. In still another embodiment of the present disclosure, the device200for repairing the solar cell module further has multiple pairs of the first terminals210and the second terminals220, and the first terminals210and the second terminals220are electrically connected to the power supply device230. Thereby, in this embodiment, each pair of the first terminal210and the second terminal220electrically contact the two corresponding back electrode layers340, such that the biased voltage signal S is output to the solar cells300′ at the same time through equipotential, so as to repair a part of the solar cells300′. Afterward, in this embodiment, polarities of the first terminal210and the second terminal220are exchanged by a switching device of the power supply device230, and the biased voltage signal S is output to repair the remaining solar cells300′, wherein the switching device is electrically connected to the first terminal210and the second terminal220. Therefore, in this embodiment, the semiconductor crystals150or the residual thin films in the solar cells300′ are removed (oxidized) at the same time through the plurality of pairs of the first terminals210and the second terminals220.

FIG. 5is a schematic view of a biased voltage signal S according to another embodiment of the present disclosure. The biased voltage signal S further has a forward biased voltage part I and multiple continuous reversed biased voltage parts II. That is, a reversed biased voltage part II is directly connected to an end of another reversed biased voltage part II, and then the forward biased voltage part I is directly connected to an end of the last reversed biased voltage part II. In this manner, after accepting the energy from the continuous reversed biased voltage parts II and being oxidized, the semiconductor crystals150or the residual thin films in the solar cells300′ accept the energy from the forward biased voltage part I. Therefore, under the same time, as compared with the conventional art, the present disclosure may achieve the same repairing effect through a shorter repairing time course.

FIG. 6is a schematic view of a biased voltage signal S according to still another embodiment of the present disclosure. In addition to the step-like waveform of the reversed biased voltage part II, in still another embodiment of the present disclosure, the voltage value of the reversed biased voltage part II is a fixed value. Therefore, by using the reversed biased voltage part II as shown inFIG. 6, in this embodiment, the time of repairing the solar cells300′ of the present disclosure is further reduced.

To sum up, the waveform of the reversed biased voltage part of the present disclosure is in a step-like shape, such that under a unit time and a fixed voltage drop, the step-like waveform of the reversed biased voltage of the present disclosure may provide relatively more energy to the semiconductor crystals or residual thin films that are not completely removed, so as to oxidize the semiconductor crystals or the residual thin films. In addition, the biased voltage signal of the present disclosure may further have a plurality of continuous reversed biased voltage parts, so that under the same time, as compared with the conventional art, the present disclosure may achieve the same repairing effect through a shorter repairing time course.