Abstract
This paper produces CdS thin film using ITO glass as substrates. The MDS (Multiplex Deposition Sputter System) was used to produce devices by changing RF power and deposition time. The manufactured specimen was analyzed for its optical properties. The purpose of this paper is to find the fabrication conditions that can be applied to the photo-absorbing layer of solar cells. When RF power was 50W and deposition time was 10 minutes, the thickness was measured at 64Å. At 100W, the thickness was measured at 406Å and at 150 W, the thickness was measured at 889Å. Thin films were found to increase in thickness as RF power increased. As a result of the light transmittance measurement, 550-850nm was observed to have a transmittance of approximately 70% or more when the RF power was 50W, 100W, and 150W. Increasing RF power increased thickness and increased particle size, resulting in increased thin film density, resulting in reduced light transmittance. When RF power was 100W and deposition time was 15 minutes, the band gap was calculated at 3.998eV. When deposition time is 20 minutes, it is 3.987eV, 150W is 3.965eV at 15 minutes, and 3.831eV at 20 minutes. It was measured that the band gap decreased as the RF power increased. At XRD analysis, diffraction peaks at 2Θ=26.44 could be observed regardless of changes in RF power and deposition time. The FWHM was shown to decrease with increasing deposition time. And it was measured that the particle size increased as RF power was constant and deposition time was increased.
본 논문은 ITO 유리를 기판으로 사용하여 CdS 박막을 제작하였다. MDS (Multiplex Deposition Sputter System)을 이용하여 RF power와 증착시간을 변화시키면서 소자를 제작하였다. 제작된 시편은 광학적 특성에 대해 분석을 하였다. 본 논문의 목적은 태양전지의 광흡수층에 적용될 수 있는 제작조건을 찾는 것이다. RF power가 50W이고 증착 시간이 10분 일 때, 두께는 64Å로 측정되었다. 100W일?, 두께는 406Å로 측정되었고, 150W일 때는 두꼐는 889Å로 측정되었다. 박막은 RF power가 증가할수록 두께가 증가되는 것을 확인하였다. 광투과율 측정한 결과, 550~850nm는 RF power가 50W, 100W, 150W일 때 모두 투과율이 대략 70% 이상으로 관찰되었다. RF power가 증가되면 두께가 증가되고 입자 크기가 커지므로 박막의 밀도가 증가되어 광투과율이 감소되었다. RF power를 100W로 하고 증착시간을 15분 일 때, 밴드갭은 3.998eV로 계산되었다. 증착시간을 20분일 때, 3.987eV이고 150W는 15분에서는 3.965eV이며 20분에서는 3.831eV이다. RF power가 증가하면 밴드갭이 증가하는 것으로 측정되었다. XRD 분석에서 RF power와 증착시간의 변화에 관계없이 2Θ=26.44에서의 회절 피크를 관찰할 수가 있었다. 반치폭은 증착시간이 증가하면 감소되는 것을 알 수가 있었다. 그리고 RF power를 일정하게 하고 증착시간을 증가하면 입자크기는 증가되는 것으로 측정되었다.