Hydrogen-mediated carrier modulation in CH₃NH₃PbI₃ thin films by multi-source co-evaporation

Abstract This study presents a four-source co-evaporation technique to precisely control the electrical conductivity of CH 3 NH 3 PbI 3 thin films. By incorporating hydrogen gas (H 2 ) alongside CH 3 NH 2 , HI, and solid-source PbI 2 , we achieved both n -type and p -type doping (∼10 13 –10 14 cm −3 ) while minimizing iodine vacancies (∼10 15 –10 17 cm −3 ). Our circuit current experiments, supported by the defect chemistry model, demonstrate that hydrogen incorporation increases electron carrier density while maintaining low iodine vacancy concentrations with minor impact on crystal quality. X-ray diffraction analysis confirmed that hydrogen incorporation causes lattice expansion.