An IBC solar cell is a type of high-efficiency crystalline silicon solar cell that has no electrodes on the front side, but instead has interdigitated positive and negative metal contacts on the back side. This design reduces the shading and resistance losses caused by the front metal grid, and increases the light absorption and current collection. The IBC solar cell technology was first developed by SunPower, and has achieved a record efficiency of 25.2% in the laboratory. IBC solar cells are more expensive and complex to produce than conventional solar cells, but they offer higher performance and reliability. For the customized solar panels, mostly use the IBC cell plus SMT technology for the mini solar panel, ensure an high voltage and high performance output.
IBC solar cells are a type of high-efficiency silicon-based solar cell technology that places all electrodes on the back of the cell, avoiding the shading and resistance losses caused by the front metal grid. IBC solar cells have achieved efficiencies of over 25%, and are expected to further increase. China is an important producer and market of IBC solar cells, and has made significant technological progress and breakthroughs in this field in recent years.
• In December 2023, the International Solar Energy Research Center (ISC Konstanz) and China National Power Investment Group (SPIC Solar) jointly released a new IBC solar cell technology that achieved an efficiency of over 24% in large-scale production. This is the highest efficiency among known crystalline silicon solar cells that do not use carrier-selective contacts. The technology uses an improved screen-printing process that can achieve an open-circuit voltage of over 700 millivolts. In addition, the technology also developed an advanced module connection technology that is simpler than traditional double-sided contact solar cells. The next step is to use the process developed and patented by ISC Konstanz to achieve low-cost bipolar carrier-selective contacts. With the industrialization of this process, it is possible to achieve an efficiency of over 25% at low cost.
• In March 2022, the Institute of Semiconductors of the Chinese Academy of Sciences (CAS-IMEC) and the Institute of Microelectronics of the Chinese Academy of Sciences (CAS-IEMN) jointly released a new POLO-IBC solar cell technology that achieved an efficiency of 23.71% in the laboratory. The technology uses polycrystalline silicon oxide (POLO) as a carrier-selective contact, which can effectively reduce the surface recombination rate and contact resistance. The technology also uses laser cutting and laser welding processes to achieve high-quality and low-loss module packaging.
• In January 2021, the Belgian Microelectronics Research Center (Imec) and the Institute of Semiconductors of the Chinese Academy of Sciences (CAS-IMEC) jointly released a new three-dimensional multi-ribbed ribbon connection technology that can be used for IBC solar cell modules. The technology uses specially designed multi-ribbed ribbons that can increase the module output power and reliability without increasing the number and contact area of solder joints. The technology is the first to use IBC solar cells in multi-chip modules, and shows good stability and durability.
• In July 2020, the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) released a new IBC solar cell technology that achieved an efficiency of 25% in the laboratory. The technology uses oxide/nitride/oxide (ONO) as a bipolar carrier-selective contact, which can effectively suppress surface recombination and interface defects. The technology is evolved from the previous 24.4% efficiency cell, by optimizing process parameters and material characteristics, further improving cell performance.
