physica status solidi (RRL) - Rapid Research Letters · 2014 · 26 citations · 11 references
EngineeringElectrical EngineeringMaterials ScienceOptoelectronicsSemiconductor DevicesSemiconductor MaterialsCarrier TransportPhotovoltaic DevicesSemiconductor Device MaterialsSemiconductor PhysicsSilicon MaterialsSolar CellsCapture Cross SectionsCharge TrapsDirect DetectionLight-induced DegradationSilicon Solar CellsSilicon WafersTrap CharacterizationTraps
In solar cells fabricated from boron-doped Cz-Si wafers minority and majority carrier traps were detected by deep level transient spectroscopy (DLTS) after so-called “light-induced degradation” (LID). The DLTS signals were detected from mesa-diodes with the full structure of the solar cells preserved. Preliminary results indicate metastable traps with energy levels positioned at EV + 0.37 eV and EC – 0.41 eV and apparent carrier capture cross-sections in the 10–17–10–18 cm2 range. The concentration of the traps was in the range of 1012–1013 cm–3. The traps were eliminated by annealing of the mesa-diodes at 200 °C. No traps were detected in Ga-doped solar cells after the LID procedure or below the light protected bus bar locations in B-doped cells. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)
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