Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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Preparation of Cadmium-free Buffer Layers for CIGS Solar Cells

CIGS 태양전지용 Cd-Free 버퍼층 제조

  • Moon, Jee Hyun (Department of Chemical & Biological Engineering, Gachon University) ;
  • Kim, Ji Hyeon (Department of Chemical & Biological Engineering, Gachon University) ;
  • Yoo, In Sang (Department of Chemical & Biological Engineering, Gachon University) ;
  • Park, Sang Joon (Department of Chemical & Biological Engineering, Gachon University)
  • 문지현 (가천대학교 화공생명공학과) ;
  • 김지현 (가천대학교 화공생명공학과) ;
  • 유인상 (가천대학교 화공생명공학과) ;
  • 박상준 (가천대학교 화공생명공학과)
  • Received : 2014.08.04
  • Accepted : 2014.10.14
  • Published : 2014.12.10
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Abstract

Indium hydroxy sulfide ($In(OH)_xS_y$) as a cadmium (Cd)-free buffer layer for $CuInGaSe_2$ (CIGS) solar cells was prepared by the chemical bath deposition (CBD) and the reaction time was optimized. The band gap energy and transmittance data alongside the thickness results from the direct observation with focused ion beam system (FIB) could be a powerful tool for optimizing the conditions. In addition, X-ray diffractometer (XRD), X-ray photoelectron microscopy (XPS), and scanning electron microscope (SEM) were also employed for the layer characterization. The results indicated that the optimum reaction time for $In(OH)_xS_y$ buffer layer deposition by CBD was 20 min at $70^{\circ}C$ under the conditions employed. At the optimum conditions, the buffer layer thickness was near 57 nm and the band gap energy was 2.7 eV. In addition, it was found that there was no XPS peak shift in between the buffer layers deposited on molybdenum (Mo)/glass and that on CIGS layer.

CIGS 태양 전지용 cadmium (Cd)-free $In(OH)_xS_y$ 버퍼층을 화학적 용액성장법을 이용해서 형성시켰고 최적 반응시간을 파악하였다. 투과율 측정과 함께 이온집적빔 시스템으로 직접 박막을 관찰해서 박막성장 조건을 최적화 하였으며 X선 회절분석법과 X선 광전자 분광법, 주사현미경을 이용해서 박막의 특성을 파악하였다. 그 결과 $In(OH)_xS_y$ 버퍼층의 증착을 위한 최적 반응 시간은 온도 섭씨 $70^{\circ}$의 조건에서 20 min임을 확인하였으며, 이때의 버퍼층의 두께는 57 nm 가량이었고 밴드갭 에너지는 2.7 eV를 나타내었다. 아울러 molybdenum (Mo)층과 CIGS층 위에서 $In(OH)_xS_y$ 버퍼층을 형성시키는 경우에 XPS 피크의 차이는 볼 수 없었다.

Keywords

References

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