"In this work, the Field’s metal was studied as an alternative cathode in perovskite solar cells (PSC-FM) and their performance was compared to reference cells with Ca/Ag cathodes (PSC-Ca/Ag). The structure of the solar cells was: glass/ITO/PEDOT:PSS/CH3NH3PbI3-xClx/PC71BM/Cathode. An analysis of the interface of the PC71BM/cathode was made using SEM, AFM and LBIC. It was found that the interface with FM showed defects such as “empty spaces” that would make a bad physical contact between both surfaces. However, the photovoltaic performance of perovskite solar cells showed comparable efficiencies; for PSC-FM the PCE was 10.2% meanwhile for PSCCa/Ag was 10.5%. Therefore it is shown that the eutectic mixture of Field’s metal is a good alternative cathode which does not require special conditions to be deposited and it is not expensive to acquire."