Two new porphyrins that incorporate thiophene substituents as spacers between the conjugated

porphyrin core and the anchoring cyanoacrylate group have been synthesised. The two dyes differ in the

number of thiophene bridges; porphyrin 1a has only one thiophene group and porphyrin 1b has two

thiophene rings connected by a double bond. The measured light-to-energy conversion efficiencies in 1a

and 1b were assessed using two different electrolytes, LP1 and LP2, which differ in the presence of tertbutyl

pyridine in LP1. An efficiency of 6% under standard measurement conditions has been achieved for

1a þ LP1. However, for porphyrin 1b the use of electrolyte LP1 led to lower efficiencies and a value of

approximately 4% was obtained. The differences between the two types of solar cells and the electrolytes

have been studied in-depth using photo-induced time-resolved techniques such as CE (Charge Extraction)

and TPV (Transient PhotoVoltage).