Characteristics of Mono Crystalline Silicon Solar Cell for Rear Electrode with Aluminum and Aluminum-Boron

Aluminum 및 Aluminum-Boron후면 전극에 따른 단결정 실리콘 태양전지 특성

  • 홍지화 (충북대학교 대학원 반도체공학과) ;
  • 백태현 (충북대학교 대학원 전기공학과) ;
  • 김진국 (충북대학교 대학원 반도체공학과) ;
  • 최성진 (한국에너지기술연구원) ;
  • 김남수 (충북대학교 대학원 반도체공학과) ;
  • 강기환 (한국에너지기술연구원) ;
  • 유권종 (한국에너지기술연구원) ;
  • 송희은 (한국에너지기술연구원)
  • Published : 2011.11.24

Abstract

Screen printing method is a common way to fabricate the crystalline silicon solar cell with low-cost and high-efficiency. The screen printing metallization use silver paste and aluminum paste for front and rear contact, respectively. Especially the rear contact between aluminum and silicon is important to form the back surface filed (Al-BSF) after firing process. BSF plays an important role to reduces the surface recombination due to $p^+$ doping of back surface. However, Al electrode on back surface leads to bow occurring by differences in coefficient of thermal expansion of the aluminum and silicon. In this paper, we studied the properties of mono crystalline silicon solar cell for rear electrode with aluminum and aluminum-boron in order to characterize bow and BSF of each paste. The 156*156 $m^2$ p-type silicon wafers with $200{\mu}m$ thickness and 0.5-3 ${\Omega}\;cm$ resistivity were used after texturing, diffusion, and antireflection coating. The characteristics of solar cells was obtained by measuring vernier callipers, scanning electron microscope and light current-voltage. Solar cells with aluminum paste on the back surface were achieved with $V_{OC}$ = 0.618V, JSC = 35.49$mA/cm^2$, FF(Fill factor) = 78%, Efficiency = 17.13%.

Keywords