Wet Etching To Form Junctions In Peripheral Region In Metallurgical Silicon Solar Cells And Study On Common Problems On PV Modules

Wet etching method was used to etch the periphery junctions and phosphor silicate glass (PSG) on the surfaces of the metallurgical-grade silicon solar cells. Electroluminescent was used to characterize etched devices, and the parameters were showed by BACCINI which was used to divide solar cells into different grades. The experimental results show that wet etching can improve the etch results. Periphery of cells was etched uniformly. The over etch and insufficient etch were avoided. The shunt resistance of the cell by wet etching increased over 80Ω than that etched by plasma. The reverse bias leakage current was also dropped obviously and the average conversion efficiency was improved from 17.2% to 17.5%, indicating a better performance.A systematic analysis was investigated to study the problems of running a 30MW on-grid PV system, including hot-points, module aging, power deducing, earthworm traces, cracked, mismatch and PID (Potential Induced Degradation) effect.Attending the construction of a 5MW distributed PV system and comparing the output power of PV systems for one year that have same installed capacity but with different types of inverters, the results show that the performance has no relevance of types of inverters.