Selecting non-halogenated low-toxic hole transporting materials for Roll-to-Roll perovskite solar cells using carbon electrodes oleh Ershad Parvazian, David Beynon, Olivia Jenkins, Rahul Patidar, James Mcgettrick, Samual Ngombe, Bhushan Patil, Rodrigo Garcia-Rodriguez, Karen Valadez Villalobos, Peter Davies, Mathew Davies, Trystan Watson