Boron Diffused Layer Formation Process and Characteristics for High Efficiency N-type Crystalline Silicon Solar Cell Applications

N-type 고효율 태양전지용 Boron Diffused Layer의 형성 방법 및 특성 분석

  • Shim, Gyeongbae (College of Information and Communication Engineering, Sungkyunkwan University) ;
  • Park, Cheolmin (Department of Energy Science, Sungkyunkwan University) ;
  • Yi, Junsin (College of Information and Communication Engineering, Sungkyunkwan University)
  • 심경배 (성균관대학교 정보통신대학) ;
  • 박철민 (성균관대학교 에너지과학과) ;
  • 이준신 (성균관대학교 정보통신대학)
  • Received : 2016.10.27
  • Accepted : 2017.02.03
  • Published : 2017.03.01


N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.


Supported by : Korea Institute Advancement of Technology (KIAT)


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