Korean Chemical Engineering Research

  • 제55권1호
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  • Pages.93-98
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  • 2017
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  • 0304-128X(pISSN)
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  • 2233-9558(eISSN)
한국화학공학회 (The Korean Institute of Chemical Engineers)
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Zn(Ox,S1-x) 버퍼층 적용을 통한 Cu2ZnSnS4 태양전지 특성 향상

Improvement of Cu2ZnSnS4 Solar Cell Characteristics with Zn(Ox,S1-x) Buffer Layer

  • 양기정 (대구경북과학기술원 태양에너지융합연구센터) ;
  • 심준형 (대구경북과학기술원 태양에너지융합연구센터) ;
  • 손대호 (대구경북과학기술원 태양에너지융합연구센터) ;
  • 이상주 (대구경북과학기술원 태양에너지융합연구센터) ;
  • 김영일 (대구경북과학기술원 태양에너지융합연구센터) ;
  • 윤도영 (광운대학교 화학공학과)
  • Yang, Kee-Jeong (Convergence Research Center for Solar Energy, Daegu Gyeongbuk Institute of Science & Technology (DGIST)) ;
  • Sim, Jun-Hyoung (Convergence Research Center for Solar Energy, Daegu Gyeongbuk Institute of Science & Technology (DGIST)) ;
  • Son, Dae-Ho (Convergence Research Center for Solar Energy, Daegu Gyeongbuk Institute of Science & Technology (DGIST)) ;
  • Lee, Sang-Ju (Convergence Research Center for Solar Energy, Daegu Gyeongbuk Institute of Science & Technology (DGIST)) ;
  • Kim, Young-Ill (Convergence Research Center for Solar Energy, Daegu Gyeongbuk Institute of Science & Technology (DGIST)) ;
  • Yoon, Do-Young (Department of Chemical Engineering, Kwangwoon University)
  • 투고 : 2016.08.26
  • 심사 : 2016.11.23
  • 발행 : 2017.02.01
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⟨ 이전 논문 다음 논문 ⟩

초록

본 실험에서는 $Cu_2ZnSnS_4$(CZTS) 태양전지의 흡수층 상부에 다양한 조성을 갖는 $Zn(O_x,S_{1-x})$ 버퍼층을 적용하여 특성 변화를 살펴보았다. $Zn(O_{0.76},S_{0.24})$, $Zn(O_{0.56},S_{0.44})$, $Zn(O_{0.33},S_{0.67})$ 그리고 $Zn(O_{0.17},S_{0.83})$의 4가지 단일막의 경우, 전자-정공의 재결합 억제에 유리한 밴드갭 구조를 나타내는 $Zn(O_{0.76},S_{0.24})$ 버퍼층을 소자에 적용했다. $Zn(O_{0.76},S_{0.24})$ 버퍼층을 소자에 적용 시, 흡수층으로부터 S가 버퍼층으로 확산되어 소자 내에서의 버퍼층은 $Zn(O_{0.7},S_{0.3})$의 조성을 나타냈다. CdS 버퍼층의 $E_V$보다 낮은 에너지 준위를 갖는 $Zn(O_{0.7},S_{0.3})$ 버퍼층은 전자-정공 재결합을 효과적으로 억제하기 때문에 CZTS 태양전지의 $J_{SC}$와 $V_{OC}$ 특성을 향상시켰다. 이를 통해 CdS 버퍼층이 적용된 CZTS 태양전지의 효율인 2.75%가 $Zn(O_{0.7},S_{0.3})$ 버퍼층 적용을 통해 4.86%로 향상되었다.

This experiment investigated characteristic changes in a $Cu_2ZnSnS_4$(CZTS) solar cell by applying a $Zn(O_x,S_{1-x})$ butter layer with various compositions on the upper side of the absorber layer. Among the four single layers such as $Zn(O_{0.76},S_{0.24})$, $Zn(O_{0.56},S_{0.44})$, $Zn(O_{0.33},S_{0.67})$, and $Zn(O_{0.17},S_{0.83})$, the $Zn(O_{0.76},S_{0.24})$ buffer layer was applied to the device due to its bandgap structure for suppressing electron-hole recombination. In the application of the $Zn(O_{0.76},S_{0.24})$ buffer layer to the device, the buffer layer in the device showed the composition of $Zn(O_{0.7},S_{0.3})$ because S diffused into the buffer layer from the absorber layer. The $Zn(O_{0.7},S_{0.3})$ buffer layer, having a lower energy level ($E_V$) than a CdS buffer layer, improved the $J_{SC}$ and $V_{OC}$ characteristics of the CZTS solar cell because the $Zn(O_{0.7},S_{0.3})$ buffer layer effectively suppressed electron-hole recombination. A substitution of the CdS buffer layer by the $Zn(O_{0.7},S_{0.3})$ buffer layer improved the efficiency of the CZTS solar cell from 2.75% to 4.86%.

키워드

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