Studies on Mechanism of Constructing Ohmic Contact between Front Electrode and Silicon based Solar Cell

  • 羅 喬陽

Student thesis: Master's Thesis

Abstract

  Since the use of green-energy has been one of the global trends the demand for solar cell increases rapidly Thus more details about manufacturing solar cells should be developed In this study mechanism of constructing ohmic contact between front electrode and Si-based solar cell will be investigated Newly-invented paste and process are used in the preparation of front electrode   In this study paste was printed with narrow line screen printing process on polycrystalline Si solar cell which has already finished the back Al printing and deposition of double anti-reflection coatings (DARCs) Then two-step firing process was applied to sinter the front electrode and obtain the ohmic contact between front electrode and solar cell The two-step firing process was accomplished in air atmosphere and reducing atmosphere The first step was in air atmosphere In this process PbO-based glass frit etched the DARCs and Ag recrystallized at the surface of Si constructing the preliminary contact The second step was in reducing atmosphere In this process CuO reduced to Cu and sintered Besides Ag nanoparticles recrystallized in the glass layer at interface due to the interactions between H2 Ag and PbO-based glass frit and the volatility of Pb constructing the ohmic contact between electrode and solar cell Scanning electron microscope (SEM) transmission electron microscopy (TEM) energy dispersive spectroscopy (EDS) and four-point probe were employed to analyze the results after each process   By experiment and analysis reaction mechanism in each stage was surmised and it was also proven that ohmic contact and good sheet resistance for front electrode could both be obtained by applying newly-invented paste and process The lowest sheet resistance of front electrode measured was 0 090 Ω/□
Date of Award2014 Aug 22
Original languageEnglish
SupervisorWen-Shi Lee (Supervisor)

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