Conjugated copolymers as doping- and annealing-free hole transport materials for highly stable and efficient p-i-n perovskite solar cells

Significant advances in organic-inorganic halide perovskite solar cells (Pero-SCs) have been achieved in recent times. In high performance Pero-SCs, poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) is an effective polymer hole transport layer (HTL), but the requisite dopants and thermal annealing may limit its application in terms of the cost and stability of the resulting devices. Therefore, doping- and annealing-free HTLs are highly demanded for the long-term development of Pero-SCs. In the present study, we designed and synthesized three block copolymers with conjugated backbones (denoted as DTS, CDT, and DTP) and applied them as HTLs in p-i-n Pero-SCs with the configuration ITO/HTL/PSBMA/MAPbI(3)(Cl)/C-60/BCP/Ag. These three materials require neither doping nor annealing as HTLs, and we obtained high power conversion efficiencies (PCEs) of 20.16%, 20.05%, and 17.60% for Pero-SCs based on DTS, CDT, and DTP, respectively. More importantly, the devices are quite tolerant to moisture and heat. The unencapsulated Pero-SCs retained over 94% of their initial PCE after 1500 h in air with a relative humidity of similar to 20%, and over 83% of their initial PCE after 400 h at 85 degrees C.

Automated summary

Recent research has focused on developing efficient organic-inorganic halide perovskite solar cells with block copolymers as hole transport layers (HTLs) that do not require doping or thermal annealing. This approach has resulted in high power conversion efficiencies (PCEs) for Pero-SCs, with devices exhibiting high tolerance to moisture and heat.