TY  - JOUR
AU  - Liao, Min
AU  - Wang, Zhaojin
AU  - Shan, Chengwei
AU  - Luo, Dengfeng
AU  - Guan, Zhongyuan
AU  - Wang, Qingqian
AU  - Zhu, Hongmei
AU  - Song, Zhulu
AU  - Wu, Dan
AU  - Kyaw, Aung Ko Ko
AU  - Wang, Kai
PY  - 2025
TI  - An ionic liquid assisted in-situ growth of large-area and high-crystal-quality perovskite single-crystal thin films
JO  - Nano Research
SN  - 1998-0124
SP  - 94907046
VL  - 18
IS  - 1
AB  - In-situ growth of perovskite single-crystal thin films (PeSCTFs) on the transport layer is crucial for achieving high-performance perovskite optoelectronic devices, such as solar cells, light emitting diodes, photodetectors, etc. However, in-situ growing PeSCTF on the transport layer with large-area, high-crystal-quality, and low-trap-density simultaneously remains challenging. This work proposes a method for in-situ growing large-area and low-trap-density MAPbBr3 SCTFs on the poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) transport layer with the assistance of cesium(I) bis(trifluoromethanesulfonyl)imide (CsTFSI) ionic liquid. After introducing the CsTFSI ionic liquid, the Cs+ ions enter the MAPbBr3 lattice, reducing the formation energy, and the coordination between the lone pair electrons of O in TFSI– and the empty orbital of Pb in MAPbBr3 passivates the dangling bond defects of Pb, facilitating the formation of MAPbBr3 SCTFs with high-crystal-quality. Moreover, the strong interaction between TFSI– and the substrate can enhance wettability and reduce the contact angle, thereby promoting faster solute diffusion and enabling the growth of larger-area MAPbBr3 SCTFs. Therefore, compared to the sample without CsTFSI addition, the MAPbBr3 SCTFs with CsTFSI addition exhibit better thermal stability, larger area (increased from 1.79 to 19.68 mm2, approximately a 10-fold increase), lower trap density (decreased from 6.86 × 1012 to 5.39 × 1012 cm–3), and higher carrier mobility (increased from 0.72 to 0.84 cm2∙V–1∙s–1). Moreover, the performance of the photodetector with CsTFSI, including responsivity, external quantum efficiency (EQE), detectivity, and response speed, also increased significantly. This work provides an effective method for the in-situ growth of PeSCTFs with large-area, high-crystal-quality, and low-trap-density simultaneously on the transport layer.
UR  - https://doi.org/10.26599/NR.2025.94907046
DO  - 10.26599/NR.2025.94907046