Dopant-free polymeric hole transport materials for highly efficient and stable perovskite solar cells. Issue 7 (13th May 2016)

• Record Type: Journal Article
• Authors: Kim, Guan-Woo; Kang, Gyeongho; Kim, Jinseck; Lee, Gang-Young; Kim, Hong Il; Pyeon, Limok; Lee, Jaechol; Park, Taiho
• Is Part Of: Energy & environmental science. Volume 9:Issue 7(2016)
• Page Start: 2326
• Page End: 2333
• Publication Date: 2016-05-13
• Subjects: Energy conversion -- Periodicals; Fuel switching -- Periodicals; Environmental sciences -- Periodicals; Environmental chemistry -- Periodicals; 333.79
• DOI: 10.1039/c6ee00709k
• Languages: English
• ISSNs: 1754-5692

Abstract

Abstract : A dopant–free polymeric hole transport material (HTM), RCP, based on benzo[1, 2- b :4, 5: b ′]dithiophene and 2, 1, 3-benzothiadiazole exhibited a high efficiency of 17.3% in a perovskite solar cell and maintained its initial efficiency for over 1400 hours. Abstract : We report 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, which results in highly efficient and stable perovskite solar cells (∼17.3% for 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. TheRCP -based perovskite solar cell exhibits the highest efficiency (17.3%) in the absence of dopants [lithium bis(trifluoromethanesulfonyl)imide and tert -butylpyridine]. 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 a hydrophobic polymer layer.RCP devices maintain their initial efficiency for over 1400 h at 75% humidity, whereas devices made of HTMs with additives fail after 900 h.