Additives-free indolo[3,2-b]carbazole-based hole-transporting materials for perovskite solar cells with three yeses: Stability, efficiency, simplicity

Indolo[3,2-b]carbazole-based hole transporting materials (HTM1–3) are developed for dopant-free perovskite solar cells (PSCs). The newly synthesized compounds studied as alternatives of conventional hole-transporting which typically require additives, characterized by low resistivity to penetration water, complicated synthesis and purification. influence substituents derivatives indolo[3,2-b]carbazole on their physical properties, e.g. ionization potentials, mobilities, the temperatures thermal transitions, is investigated using experimental theoretical tools. Ionization potentials in order HTM2 HTM1 (1.1 HTM2 (0.55 cm2V-1s?1) without additives principally stemming from small degrees energetic disorder following (73.4 meV) ~ (73.2 (59.5 meV). different combinations these parameters results power conversion efficiencies PSCs: [19.45% device containing HTM2] [18.75% PCS HTM3] [14.46% HTM1]. devices demonstrate considerably higher stability practically comparable efficiency additives-containing reference PSCs material spiro-OMeTAD.