Substrates Dependent Low Temperature Fabrication of Silver Nanoparticles Using Rapid Thermal Annealing for Light Trapping Application

This work presents a comparative study of low temperature fabrication of silver (Ag) nanoparticles (NPs) by rapid thermal annealing (RTA) of non-continuous Ag film onto various substrates such as glass, polished single-crystalline silicon (c-Si) and poly-crystalline silicon (pc-Si) with supporting growth mechanism. The RTA treatment for various time durations (5, 10, 15, 20 and 30 minutes) of Ag film has resulted into formation of uniformly distributed Ag NPs. The scanning electron microscope (SEM) measurements confirm variation in average particle size of Ag NPs for various RTA durations and show minimum particle size behavior profile irrespective of substrate surfaces. The so formed Ag NPs on glass substrates exhibit plasmonic peaks in the range of 415-435 nm. The atomic force microscope (AFM) measurement confirms prolate shape, least surface coverage area of substrate and minimal average particle size of Ag NPs to be suitable for maximizing reflection reduction of Si surface. The 20 minutes RTA treatment of non-continuous Ag film onto both c-Si and pc-Si substrate has led average reflectance reduction from 39.15% and 34.97% to 6.29% and 23.02%, respectively in 300-1100 nm wavelength region. An optimized integration of Ag NPs on Si surface can be useful for light trapping and hence can increase efficiency of Si solar cell by reflectance reduction via photocurrent increment.