Stable perovskite solar cells using thiazolo [5,4-d]thiazole-core containing hole transporting material

This work explains the synthesis of an efficient organic hole transporting material based on 4,4′-(5,5′-(thiazolo[5,4-d]thiazole-2,5-diyl)bis(furan-5,2-diyl))bis(N,N-diphenylaniline) (TP-FTzF-TP) and the replacement of poly(3,4-ethylenedio-xythiophene): poly(styrenesulfonate) (PEDOT:PSS) layer by simple O₂ plasma treatment for perovskite solar cells (PSCs). The introduction of furan spacer groups significantly tuned the absorption and the electrochemical properties of the organic hole transporting material. The ITO(O₂ plasma)/TP-FTzF-TP/CH₃NH₃PbI₃/PC₆₁BM/Au configuration based PSC exhibited a high power conversion efficiency (PCE) of ~ 16.4% which showed a momentous improvement as compared to PCEs of ~ 11.6% and ~ 10.5% achieved by ITO/PEDOT:PSS/TP-FTzF-TP/CH₃NH₃PbI₃/PC₆₁BM/Au and ITO/TP-FTzF-TP/CH₃NH₃PbI₃/PC₆₁BM/Au devices, respectively. The superior performances of PSC were accredited to fast hole injection from the valence band of CH₃NH₃PbI₃ into the suitable HOMO and a high hole mobility of TP-FTzF-TP HTM.