Microcrystalline and micromorph device improvements through combined plasma and material characterization techniques

Abstract

Hydrogenated microcrystalline silicon ( μ c -Si:H ) growth by very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) is studied in an industrial-type parallel plate KAI reactor. Combined plasma and material characterization techniques allow to assess critical deposition parameters for the fabrication of high quality material. A relation between low intrinsic stress of the deposited i-layer and better performing solar cell devices is identified. Significant solar cell device improvements were achieved based on these findings: high open circuit voltages above 520 mV and fill factors above 74% were obtained for 1 μm thick μ c -Si:H single junction cells and a 1.2 cm 2 micromorph device with 12.3% initial ( V oc=1.33 V, FF=72.4%, J sc=12.8 mA cm −2) and above 10.0% stabilized efficiencies.