DBP and C70 based inverted tandem solar cells using a simple interconnecting layer

Abstract

Inverted tandem structure cells with a simple interconnecting layer based on tetraphenyldibenzoperiflanthene (DBP) and fullerene-70 (C₇₀) were studied in this work. Two subcells using identical donor and acceptor materials were connected by a molybdenum trioxide and calcium (MoO₃/Ca) interlayer in series. An outstanding fill factor (over 80%) under concentrated power intensity has been observed. Meanwhile, the open circuit voltage is approximately equal to the sum of the two subcells, revealing the excellent properties of MoO₃/Ca as a recombination layer for tandem structured cells. On the other hand, the main loss mechanisms of charge carriers are analyzed; Schokley–Read–Hall and bimolecular recombination dominate the charge recombination in the tandem structured cells under low and high power intensities, respectively.