Printed hole-conductor-free mesoscopic perovskite solar cells with excellent long-term stability using PEAI as an additive

109PEA is successfully introduced into fully printable, hole-conductor-free PEA-MAPbI3 MPSCs in a simple method. The PCE of PEA-MAPbI3 MPSCs is 37% higher than that of MAPbI3 MPSCs, and PEA-MAPbI3 MPSCs show excellent stability by keeping 90% of origin PCE over 80 days in the air.