Characterization of Silicon Surface Passivation by Photoluminescence/Raman Spectroscopy

Maximization of the power conversion efficiency (PCE) in nanostructured silicon/ PEDOT:PSS hybrid solar cells is an active area of photovoltaic research, due to the reduced thermal budget in production of such devices in comparison to conventional silicon solar cells [1]. Surface passivation of silicon at silicon/organic interface was found to be essential for high efficiency of silicon-based photovoltaics. Surface defects and dangling bonds significantly increase the recombination rate of minority carriers, may pin the Fermi level and cause undesirable band bending at silicon interfaces [2]. Passivation methods for planar silicon surfaces that are currently available [3] are not always compatible with the nanostructured and hybrid organic/inorganic devices, for which appropriate passivation should be developed. Measuring the state of surface passivation is essential in this process. We present a method for the characterization of surface passivation of silicon by simultaneous band gap photoluminescence and Raman spectroscopy.