Numerical and experimental investigation on mc-Silicon growth process by varying the Si3N4 coating thickness of crucible

•The effect of Si3N4 thickness on impurity concentration has been investigated.•The concentration of carbon monoxide and silicon oxide in the gas domain has been investigated.•The concentration of carbon, oxygen and silicon carbide in the grown mc-Si ingots by varying the Si3N4 thickness.•200 μm Si3N4 coated crucible was used in the experiment.•The central wafer shows the minority carrier lifetime of 91.5 μs. In the present work, the bottom-opening directional solidification technique was adopted to grow multi-crystalline silicon ingot. By varying the thickness of Si3N4 coating on the quartz crucible, the variation in carbon and oxygen concentration in the ingot has been analyzed. The axis-symmetric time-dependent 2D modeling has been done to analyze heat and mass transfer within the directional solidification furnace. We have analyzed the concentration of carbon monoxide, silicon oxide, silicon carbide, carbon and oxygen in the grown mc-Si ingots by varying the Si3N4 thickness. The oxygen and carbon impurities concentration are higher for the Si3N4 coating thickness of 50 μm to 150 μm and lower for 200 μm. The minority carrier lifetimes of the top, middle and bottom wafers have been analysied. The results show that the middle wafer has higher minority carrier lifetime compared to top and bottom wafers.