Silicon nanocrystals embedded in silicon carbide: Investigation of charge carrier transport and recombination

An illumination-dependent analysis of silicon nanocrystal p-i-n solar cells is presented within the framework of the constant field approximation. Silicon nanocrystals in silicon carbide were prepared by solid-phase crystallization and contacted with doped a-Si_xC_1−x:H. This paper aims at determining the fundamental transport and recombination properties, i.e., the effective mobility lifetime product, of the nanocrystal layer at device level. Illumination-dependent current-voltage curves are modelled with a voltage-dependent collection function with only two free parameters, and excellent agreement is found between theory and experiment. An effective mobility lifetime product of 10⁻¹⁰ cm²/V is derived and confirmed independently from an alternative method.