| 초록 |
In this seminar, I will address a dopant-free polymeric hole transport material (HTM) that is based on benzo[1,2-b:4,5:b’]dithiophene and 2,1,3-benzothiadiazole and results in highly efficient and stable perovskite solar cells (~17.3% over 1400 h at 75% humidity). The HTM comprises a random copolymer (RCP), which is characterized using UV–vis absorption spectroscopy, cyclic voltammetry, space-charge-limited current, and grazing-incidence wide-angle X-ray scattering. The RCP-based perovskite solar cell exhibits the highest efficiency (17.3%) in the absence of dopants. The observed efficiency is attributed to a deep HOMO energy level and high hole mobility. In addition, the long-term stability of the device is dramatically improved by avoiding deliquescent or hygroscopic dopants and by introducing the hydrophobic polymer layer. RCP devices maintain their initial efficiency over 1400 h at 75% humidity, whereas devices made from HTMs with additives fail after 900 h. |
