The interfacial properties of organolead halide perovskite solar cells (PSCs) affect the exciton and charge-transport dynamics significantly. Thus, proper modification of the interfaces between perovskite and charge-transport layers is an efficient method to increase the power conversion efficiency (PCE) of PSCs. In this work, we explore the effect of a nonionic surfactant, that is, Triton X-100 (TX) additive, in the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) hole-transport layer. The electronic structure of TX-modified PEDOT:PSS is investigated with ultraviolet/X-ray photoelectron spectroscopy and X-ray absorption spectroscopy with various TX concentrations. The surface of the TX-modified PEDOT:PSS layer showed high TX content, and thus the semimetallic properties of PEDOT:PSS were suppressed conspicuously by its insulating nature. With the TX-modified PEDOT:PSS, the PCE of methylammonium lead iodide (MAPbI 3 ) PSCs increased significantly. To elucidate the origin of the improved device performance, the electrical properties and photoluminescence were investigated comprehensively. Consequently, it was found that the TX additive inhibits interface recombination between PEDOT:PSS and MAPbI 3 , which is caused by the suppression of semimetallic properties of the PEDOT:PSS surface. Hence, we fabricated flexible PSCs successfully using a graphene electrode and TX-modified PEDOT:PSS.
Bibliographical noteFunding Information:
This study was supported by the National Research Foundation of Korea [NRF-2018R1D1A1B07051050, 2018R1A6A1A03025582, 2017R1A2B4002442, 2018K1A3A7A09057410, and 2017R1A5A1014862 (SRC program: vdWMRC center)], and MOTIE [Ministry of Trade, Industry & Energy (10079558)], and Samsung Display Company and an Industry-Academy joint research program between Samsung Electronics and Yonsei University, and the Graduate School of Yonsei University Research Scholarship Grants in 2018. PL measurements were performed with the instrument at the Central Laboratory of Kangwon National University. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under contract no. DE-AC02-76SF00515.
All Science Journal Classification (ASJC) codes
- Materials Science(all)