Fabrication of Silicon Nanowire Array Through the Metal-induced Wet Chemical Etching Method and Its Photovoltaic Properties

• Main Authors: Tsao, Chiao-Heng, 曹巧姮
• Other Authors: Tai, Nyan-Hwa
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/87917143123478414382

碩士 === 國立清華大學 === 材料科學工程學系 === 99 === Large area SiNW arrays were successfully prepared by immersing a silicon wafer into an aqueous solution of AgNO3 and HF in an electroless metal deposition (EMD) process. However, in the process the Ag clusters easily aggregated, forming large Ag particles of various sizes, which in turn resulted in silicon wires with a large size distribution. To improve the uniformity of the SiNW arrays, uniform dispersed gold nanoparticles were used as the cathode instead, followed by the etching process using H2O2/HF solution. The growth conditions, morphologies and anti-reflection properties of SiNW arrays have been studied. Ultraviolet-visible spectroscopy analysis reveals that the SiNW has remarkable anti-reflection property, as compare with the plane silicon wafer. The reflectance of SiNW is found to decrease with increasing reaction time. The simple, inexpensive and easily scalable process to fabricate a large area silicon anti-reflection surface is a promising process for silicon-based solar cell. We used the synthesized SiNWs to fabricate solar cells. According to current-voltage curve and monochromatic incident photon-to-electron conversion efficiency(IPCE) analysis, we knew that there are many defects on the SiNW surface, which can act as recombination centers and enhance the surface recombination rate. Therefore, only the SiNW solar cell with appropriate length, which is enough to trap light but not too long for cause serious recombination, shows better performance than planer-Si solar cell.