Among the performance parameters of solar cells, many resistance factors such as series resistance, parallel resistance, and line resistance will have an important impact on the performance of solar cells, thereby affecting the normal use of solar cells in production. In order to ensure that many of its resistance parameters are within the threshold range of production standards, battery manufacturers usually use scientific solar cell performance testing equipment to effectively guarantee them after production. Millennial Solar has produced the TLM Contact Resistance Tester, which can evaluate the accurate parameters of various types of resistors through efficient, precise, and scientific optical technology, thereby helping photovoltaic enterprise users and cell manufacturers solve post-production problems they encounter. A question that cannot be scientifically evaluated!

Effect of series resistance on solar cell performance

When the series resistance increases, the short-circuit current of the solar cell will decrease, because a voltage drop will occur when the current passes through the resistor, resulting in a decrease in the effective voltage of the cell, thereby reducing the photoelectric conversion rate of the solar cell. At the same time, increasing the series resistance will also reduce the fill factor of the solar cell, because the fill factor is the ratio of the maximum output power of the solar cell to the ideal output power, and the ideal output power is the output power assuming that the cell has no internal resistance. Therefore, the larger the series resistance, the larger the gap between the ideal output power and the maximum output power will be, and the smaller the fill factor will be. The fill factor is an important parameter for evaluating the output characteristics of solar cells. It directly determines the output power of the solar cell. Therefore, the smaller the series resistance, the greater the fill factor and the higher the output power.

Important factors affecting the value of solar cell line resistance

The value of the line resistance is affected by factors such as the structure, material and process of the solar cell. The thickness, doping concentration, square resistor defect density, etc. of the silicon wafer will all affect the value of the silicon wafer base resistance; the width, height, and The shape, material, etc. will all affect the value of the grid line resistance; the thickness, material, and contact area of the electrode will all affect the value of the electrode resistance; the cleanliness, surface passivation, and welding quality of the solar cells will all affect the value of the contact resistance. Therefore, in order to reduce the line resistance and improve the performance of solar cells, it is necessary to optimize the structural design of solar cells, select appropriate materials, control process parameters, and ensure product quality.

Effect of parallel resistance on solar cells

In addition to series resistance, solar cells also have parallel resistance, which is a resistance caused by the unsatisfactory P-N junction of the solar cell or the presence of impurities near the junction, resulting in junction short circuit or leakage. The parallel resistance reflects the leakage level of the solar cell, which will affect the open circuit voltage of the solar cell, but has basically no effect on the short circuit current. When the parallel resistance decreases, the open circuit voltage will decrease because the leakage current will increase, resulting in a decrease in the effective voltage of the battery, thereby reducing the photoelectric conversion rate of the solar cell. At the same time, reducing the parallel resistance will also reduce the fill factor of the solar cell, because the parallel resistance will affect the maximum power point of the solar cell, causing it to deviate from the ideal maximum power point. Therefore, the smaller the parallel resistance, the maximum power point will be different from the ideal maximum power. The larger the gap between the points, the smaller the fill factor will be. Therefore, in order to reduce the parallel resistance and improve the performance of solar cells, it is necessary to reduce the influence of unsatisfactory P-N junctions or impurities of solar cells, improve the junction quality of solar cells, and reduce leakage.

TLM Contact Resistance Tester

E-mail:market@millennialsolar.cn

In solar cell electrode optimization, contact resistance is an important aspect that needs to be considered. The value of contact resistance is not only related to the contact image, but also related to the diffusion process and sintering process. Using the TLM Contact Resistance Tester produced by Millennial Solar to measure contact resistivity can reflect problems in diffusion, electrode production, sintering and other processes. And the contact resistivity test and line resistance test provided by this equipment can be switched at will.

●The measurement range can reach 0.1~120mΩ*cm＾2;

● Static test repeatability ≤1%, dynamic test repeatability ≤3%

● Line resistance measurement accuracy can reach 5% or 0.1Ω/cm

● Contact resistivity test and line resistance test can be switched at will

● A variety of probe heads can be customized for measurement and analysis

Resistance is an important factor affecting the performance of solar cells. It will reduce parameters such as short-circuit current, open-circuit voltage, fill factor and output power of solar cells, thereby reducing the photoelectric conversion rate of solar cells. In order to understand the accurate parameters and degree of resistance affecting its performance, TLM Contact Resistance Tester can be used to detect it, thus helping cell manufacturers to timely optimize various resistance factors based on scientific basis and improve the performance of solar cells. Make effective adjustments to the production so that the solar cells can be put into use correctly!