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Keywords:

  • amorphous silicon;
  • heterojunctions;
  • solar cells;
  • surface passivation

In this work, the influence of electrodes' distance upon the properties of amorphous silicon (a-Si:H) deposited by plasma-enhanced chemical vapor deposition method on both intrinsic and doped a-Si:H films is investigated in terms of their electrical, optical, and structural characteristics. For this purpose, Fourier-transform infra-red and secondary-ion mass-spectroscopy as well as photoconductance decay, spectral ellipsometry, and conductivity measurements are employed. Electrodes' distance is varied from 20 to 120 mm. Regarding the passivation quality of the a-Si:H film an optimum electrodes' distance of 60 mm is found. In addition, electrodes' distance is detected to have a great influence on the accelerated initial growth rate, which strongly diminishes with increasing distance. Thus, electrodes' distance also determines the overall thickness of thin intrinsic a-Si:H films being particularly interesting for utilization in heterojunction solar cells. With doped a-Si:H films, however, electrodes' distance influences mainly the dopant concentration in the films and therewith their conductivity.