Best solar cell characteristics for cells sensitized with [Fe(cpbmi)₂](PF₆)₂ (reference), [Fe(cpbmi)(dtapbmi)](PF₆)₂ and [Fe(cpbmi)(daapbmi)](PF₆)₂. Open-circuit voltage (V_oc), short-circuit current density (J_sc), short-circuit current density obtained from integration of the IPCE spectrum with respect to the AM1.5G solar spectrum (J_sc,IPCE), fill-factor (FF), power conversion efficiency (PCE) and dye loading are included (see ESI.10 for details). Average of four devices in parentheses.

Dye	V OC (V)	J SC (mA cm−2)	J SC,IPCE (mA cm−2)	FF	PCE (%)	Dye loading (10−5 mmol cm−2)
[Fe(cpbmi)2](PF6)2	0.466 (0.46 ± 0.02)	2.09 (1.9 ± 0.2)	2.14	0.752 (0.74 ± 0.1)	0.73 (0.63 ± 0.07)	22.1
[Fe(cpbmi)(dtapbmi)](PF6)2	0.512 (0.50 ± 0.01)	3.52 (3.3 ± 0.2)	3.50	0.724 (0.714 ± 0.08)	1.31 (1.2 ± 0.1)	9.87
[Fe(cpbmi)(daapbmi)](PF6)2	0.416 (0.40 ± 0.02)	3.23 (2.7 ± 0.4)	2.80	0.694 (0.69 ± 0.1)	0.93 (0.8 ± 0.2)	6.55