Figure 2. a) Current density-Voltage (J -V ) curves; b) Corresponding EQE spectra; c) J phversus V eff curves of the optimized binary and ternary OSCs; d) Statistics of PCE and correspondingJ SC values for single-junction OSCs based on PBDB-T and SMAs.
The integrated J SC values of the PBDB-T: BZ4F-O-1, PBDB-T: BZO-4Cl and PBDB-T: BZ4F-O-1: BZO-4Cl based devices calculated from the external quantum efficiency (EQE) curves (Figure 2b) are 19.49, 25.80, and 26.50 mA cm-2, respectively, which agree well with the measured J SCs fromJ -V curves within a deviation of 5%. The EQE spectra valley at the 560-780 nm range of the PBDB-T: BZO-4Cl blend was compensated by introducing BZ4F-O-1 as the third component, thus leading to a significantly integrated J SC increase of 1.29 mA cm-2 (560-780 nm). Besides, the maximum EQE value is enhanced from 78.53% to 82.39%.
Table 2. The optimal photovoltaic parameters of the binary and ternary OSCs under 1 sun illumination.