Optical simulation and experimental determination of the effect of subcell sequence in tetraphenyldibenzoperi-flanthene- and phthalocyanine-based tandem solar cells

摘要

In this work, series-connected double-junction tandem solar cells were fabricated by employing the complementary absorbing donors of tetraphenyldibenzoperiflanthenc (DBP) and chloroaluminum phthalocyanine (ClAlPc). The tandem cell shows a high open circuit voltage of 1.57 V, summing those of single cells. The optical simulation and experimental results both demonstrate that the subcell (SC) sequence plays an important role in photocurrent and till factor for tandem cells. It is helpful for current matching to use CI AlPc as a donor in the bottom SC for the ClAIPc-DBP system, because the power conversion efficiency (η_(PCE)) is increased by 1% in the ClAIPc-DBP normal tandem cell relative to the DBP-ClAlPc reverse tandem cell. The simulated external quantum efficiency (EQE) spectra of the SCs in the DBP-ClAlPc reverse cell overlap with each other thus resulting in a current mismatch. Via optical modeling, an optimized ClAIPc-DBP norma! tandem cell exhibits a η_(PCE) of 3.24% by slightly tuning layer thickness.