PEDOT:PSS emitters on multicrystalline silicon thin-film absorbers for hybrid solar cells

We fabricated an efficient hybrid solar cell by spin coating poly(3,4-ethylene-dioxythiophene): polystyrenesulfonate (PEDOT: PSS) on planar multicrystalline Si (mc-Si) thin films. The only 5 mu m thin Si absorber layers were prepared by diode laser crystallization of amorphous Si deposited by electron beam evaporation on glass. On these absorber layers, we studied the effect of SiOx and Al2O3 terminated Si surfaces. The short circuit density and power conversion efficiency (PCE) of the mc-Si/Al2O3/PEDOT: PSS solar cell increase from 20.6 to 25.4mA/cm(2) and from 7.3% to 10.3%, respectively, as compared to the mc-Si/SiOx/PEDOT: PSS cell. Al2O3 lowers the interface recombination and improves the adhesion of the polymer film on the hydrophobic mc-Si thin film. Open circuit voltages up to 604mV were reached. This study demonstrates the highest PCE so far of a hybrid solar cell with a planar thin film Si absorber. (C) 2015 AIP Publishing LLC.