The Formation Mechanism of (001) Facet Dominated alpha-FAPbI(3) Film by Pseudohalide Ions for High-Performance Perovskite Solar Cells

Li, Shengwen1; Xia, Junmin1; Wen, Zhaorui1; Gu, Hao1; Guo, Jia1; Liang, Chao1; Pan, Hui1; Wang, Xingzhu2; Chen, Shi1

2023-04-01

10.1002/advs.202300056

ADVANCED SCIENCE   影响因子和分区

2198-3844

Formamidinium lead triiodide (alpha-FAPbI(3)) has been widely used in high-efficiency perovskite solar cells due to its small band gap and excellent charge-transport properties. Recently, some additives show facet selectivity to generate a (001) facet-dominant film during crystallization. However, the mechanism to realize such (001) facet selectivity is not fully understood. Here, the authors attempted to use three ammonia salts NH4X (X are pseudohalide anions) to achieve better (001) facet selectivity in perovskite crystallization and improved crystallinity. After addition, the (001) facet dominance is generally increased with the best effect from SCN- anions. The theoretical calculation revealed three mechanisms of such improvements. First, pseudohalide anions have larger binding energy than the iodine ion to bind the facets including (110), (210), and (111), slowing down the growth of these facets. The large binding energy also reduces nucleation density and improves crystallinity. Second, pseudohalide ions improve phase purity by increasing the formation energies of the delta-phase and other hexagonal polytypes, retarding the alpha- to delta-phase transition. Third, the strong binding of these anions can also effectively passivate the iodine vacancies and suppress nonradiative recombination. As a result, the devices show a power conversion efficiency of 24.11% with a V-oc of 1.181 V.

(001) facet binding energy DFT calculation perovskite solar cell pseudohalide anions

SCI ; EI

英语

其他

Macau Science and Technology Development Fund["FDCT-0096/2020/A2","FDCT-0013/2021/AMJ","FDCT-0082/2022/A2"] ; UM's research funds["MYRG2020-00283-IAPME","MYRG2022-00266-IAPME"]

Chemistry ; Science & Technology - Other Topics ; Materials Science

Chemistry, Multidisciplinary ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000974392300001

WILEY

20231714021276

Additives ; Ammonia ; Conversion efficiency ; Crystallinity ; Energy gap ; Iodine ; Ions ; Lead compounds ; Perovskite ; Perovskite solar cells

Minerals:482.2 ; Energy Conversion Issues:525.5 ; Solar Cells:702.3 ; Physical Chemistry:801.4 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804 ; Inorganic Compounds:804.2 ; Crystalline Solids:933.1

Web of Science

1.Univ Macau, Inst Appl Phys & Mat Engn, Macau 999078, Peoples R China
2.Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 418055, Guangdong, Peoples R China

Li, Shengwen,Xia, Junmin,Wen, Zhaorui,et al. The Formation Mechanism of (001) Facet Dominated alpha-FAPbI(3) Film by Pseudohalide Ions for High-Performance Perovskite Solar Cells[J]. ADVANCED SCIENCE,2023,10(18).

Li, Shengwen.,Xia, Junmin.,Wen, Zhaorui.,Gu, Hao.,Guo, Jia.,...&Chen, Shi.(2023).The Formation Mechanism of (001) Facet Dominated alpha-FAPbI(3) Film by Pseudohalide Ions for High-Performance Perovskite Solar Cells.ADVANCED SCIENCE,10(18).

Li, Shengwen,et al."The Formation Mechanism of (001) Facet Dominated alpha-FAPbI(3) Film by Pseudohalide Ions for High-Performance Perovskite Solar Cells".ADVANCED SCIENCE 10.18(2023).