Enhanced performance of a polymer solar cell upon addition of free-standing, freshly etched, photoluminescent silicon nanocrystals

We demonstrate an organic-inorganic hybrid solar cell using poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C ₆₁-butyric acid methyl ester (PCBM) and silicon nanocrystals (Si-NCs). To achieve an enhanced response in the hybrid layer, Si-NCs were freshly etched and blended with P3HT/PCBM. The incorporation of Si-NC _s into the bulk heterojunction structure induced the coupling of optical excitation between the polymers and Si- NC _s and led to an extended optical excitation response. A hybrid solar cell exhibited a 26% increase in J _SC relative to an identical cell prepared without the Si-NC _s. Consequently, improved power conversion efficiency is obtained by the addition of Si-NC _s into polymers.