Abstract
Noise spectroscopy as a highly sensitive method for non-destructive diagnostics of semiconductor devices
was applied to solar cells based on crystalline silicon with a view to evaluating the quality and reliability
of this solar cell type. The experimental approach was used in a reverse-biased condition where the internal
structure of solar cells, as well as pn-junction itself, was electrically stressed and overloaded by a strong
electric field. This gave rise to a strong generation of a current noise accompanied by local thermal instabilities,
especially in the defect sites. It turned out that local temperature changes could be correlated
with generation of flicker noise in a wide frequency range. Furthermore, an electrical breakdown in a nonstable
form also occurred in some specific local regions what created micro-plasma noise with a two-level
current fluctuation in the form of a Lorentzian-like noise spectrum. The noise research was carried out on
both of these phenomena in combination with the spectrally-filtered electroluminescence mapping in the
visible/near-infrared spectrum range and the dark lock-in infrared thermography in the far-infrared range.
Then the physical origin of the light emission from particular defects was searched by a scanning electron
microscope and additionally there was performed an experimental elimination of one specific defect by the
focused ion beam milling.
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