Reversing an S-kink effect caused by interface degradation in organic solar cells through gold ion implantation in the PEDOT: PSS layer - Brenes-Badilla, D.; Coutinho, D. J.; Amorim, D. R. B.; Faria, Roberto Mendonça; Salvadori, Maria Cecília Barbosa da Silveira (Journal of Applied Physics, 2018)