Researchers at the SSN College of Engineering, Chennai, have claimed that they have developed high-performance multicrystalline silicon ingots through the directional solidification (DS) method.

The researchers explained that multicrystalline silicon has a less favorable crystalline structure and low-cost compared to monocrystalline silicon. The efficiency of solar cells is affected by impurities, dislocations, and von Mises stress, a value used to determine if a given material will fracture.

In their report, the researchers said that it is essential to optimize the temperature profile to reduce impurities and von Mises stress for solar photovoltaic applications.

The researchers used a transient global heat transfer method to optimize the temperature profile of the directional solidification process to develop high-performance multicrystalline silicon ingots.

The solidification process is dependent on the furnace parameters that influence the thermal condition and side insulation movement. These factors control the solidification process to obtain optimal growth conditions to produce high-quality silicon ingots that can improve solar cells’ efficiency.

The researchers controlled the temperature in the DS furnace with a thermocouple. This control parameter determined the condition in the DS furnace to improve the quality of solidified silicon ingot.

“The transient simulation is performed to analyze the effect of optimized temperature profile which gives slightly convex interface, lower carbon impurities and von Mises stress in the multicrystalline silicon ingots. The result may help further optimize the control of the process parameters,” the researchers said.

The Union Ministry of New and Renewable Energy supported the research project.

In October 2020, HighLine Technology GmbH, a spin-off of Fraunhofer Institute for Solar Energy System ISE, claimed that it had developed a new dispensing technology, enhancing the electricity yield of silicon solar cells. The company has plans to commercialize this technology.

Mercom had earlier reported that researchers at the Fraunhofer Institute for Integrated Systems and Device Technology claimed that they had identified how impurities were formed in silicon crystals during their manufacturing process.

Image credit: ArticCynda, CC0, via Wikimedia Commons