Highly efficient organic tandem solar cell based on SubPc:C70 bulk heterojunction

Highly efficient organic tandem solar cell with peak power conversion efficiency (PCE) of 7.66% has been demonstrated by simply stacking two same boron subphthalocyanine (SubPc):C-70 bulk heterojunction devices, with a high active inter-connecting layer composed of bathophenanthroline (Bphen)/Silver/hexadecafluoro-copper-phthalocyanine (F16CuPc)/MoO3. We find that F16CuPc plays an important role which extends the recombination zone, facilitates the extraction of hole and the carrier recombination. The measured PCE of the tandem solar cell corresponds to a 38% increase compared to that the optimal single cell. (C) 2014 Elsevier B.V. All rights reserved.