Advances in the Characterization of Compositionally-graded Layers in Amorphous Semiconductor Solar Cells by Real Time Spectroellipsometry Proceedings Paper (Web of Science)

abstract

  • AbstractWe have developed a real time spectroellipsometry data analysis procedure that allows us to characterize compositionally- graded amorphous semiconductor alloy thin films prepared by plasma-enhanced chemical vapor deposition (PECVD). As an example, we have applied the analysis to obtain the depth-profile of the optical gap and alloy composition with ≤15 Å resolution for a hydrogenated amorphous silicon-carbon alloy (a-Si1−xCx:H) film prepared by continuously varying the gas flow ratio z=[CH4]/{[CH4]+[SiH4]} in the PECVD process. The graded layer has been incorporated at the p/i interface of widegap a-Si1−xCx:H (x∼0.05) p-i-n solar cells, and consistent improvements in open-circuit voltage have been demonstrated. The importance of the graded-layer characterization is the ability to relate improvements in device performance directly to the physical properties of the interface layer, rather to the deposition parameters with which they were prepared.

authors

  • Collins, Robert W
  • Kim, Sangbo
  • Koh, Joohyun
  • Burnham, J. S.
  • Jiao, Lihong
  • Chen, Ing-Shin
  • Wronski, C. R.

publication date

  • 1996

published in

start page

  • 443

volume

  • 420