Evaluation of the Passivation Effects of PEDOT:PSS on Inverted Perovskite Solar Cells

摘要

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is apopular hole transport material in perovskite solar cells (PSCs). However,the devices with PEDOT:PSS exhibit large open-circuit voltage (V_(oc)) loss andlow efficiency, which is attributed to mismatched energy level alignmentand the poor interface of PEDOT:PSS and perovskite. Here, three polymeranalogues to polyaniline (PANI), PANI–carbazole (P1), PANI–phenoxazine(P2), and PANI–phenothiazine (P3) are designed with different energy levelsto modify the interface between PEDOT:PSS and the perovskite layer andimprove the device performance. The effects of the polymers on the deviceperformance are demonstrated by evaluating the work function adjustment,perovskite growth control, and interface modification in MAPbI_3-based PSCs.Low bandgap Sn–Pb-based PSCs are also fabricated to confirm the effectsof the polymers. Three effects are evaluated through the comparison studyof PEDOT:PSS-based organic solar cells and MAPbI3 PSCs based on thePEDOT:PSS modified by P1, P2, and P3. The order of contribution for thethree effects is work function adjustment > surface modification > perovskitegrowth control. MAPbI_3 PSCs modified with P2 exhibit a high V_(oc) of 1.13 Vand a high-power conversion efficiency of 21.06. This work providesthe fundamental understanding of the interface passivation effects forPEDOT:PSS-based optoelectronic devices.