TY - JOUR
T1 - Improved Thermal Stability and Film Uniformity of Halide Perovskite by Confinement Effect brought by Polymer Chains of Polyvinyl Pyrrolidone
AU - Wu, Shuyue
AU - Lin, Siyuan
AU - Shi, Zhiqiang
AU - Guo, De'en
AU - Huang, Han
AU - Zhou, Xuefan
AU - Zhang, Dou
AU - Zhou, Kechao
AU - Zhang, Wenhao
AU - Hu, Yue
AU - Zhou, Conghua
N1 - Funding Information:
C. Zhou thanks the financial support of the National Natural Science Foundation of China (NSFC, No. 61774170), and the Key Scientific Research Project of Education Department of Hunan Province (22A0005). Y. Hu acknowledges the support from the National Natural Science Foundation of China (NSFC, No. 22075094).
Publisher Copyright:
© 2023 Wiley-VCH GmbH.
PY - 2023/3/17
Y1 - 2023/3/17
N2 - Polyvinyl pyrrolidone (PVP) is doped to PbI2 and organic salt during two-step growth of halideperovskite. It is observed that PVP molecules can interact with both PbI2 and organic salt, reduce the aggregation and crystallization of the two, and then slow down the coarsening rate of perovskite. As doping concentration increases from 0 to 1 mM in organic salt, average crystallite size of perovskite decreases monotonously from 90 to 34 nm; Surface fluctuation reduces from 259.9 to 179.8 nm at first, and then increases; Similarly, surface roughness decreases from 45.55 to 26.64 nm at first, and then rises. Accordingly, a kind of “confinement effect” is resolved to crystallite growth and surface fluctuation/roughness, which helps to build compact and uniform perovskite film. Density of trap states (t-DOS) is cut down by ≈60% at moderate doping (0.2 mM). Due to the “confinement effect”, power conversion efficiency of perovskite solar cells is improved from 19.46 (±2.80) % to 21.50 (±0.99) %, and further improved to 24.11% after surface modification. Meanwhile, “confinement effect” strengthens crystallite/grain boundaries and improves thermal stability of both film and device. T80 of device increases to 120 h, compared to 50 h for reference ones.
AB - Polyvinyl pyrrolidone (PVP) is doped to PbI2 and organic salt during two-step growth of halideperovskite. It is observed that PVP molecules can interact with both PbI2 and organic salt, reduce the aggregation and crystallization of the two, and then slow down the coarsening rate of perovskite. As doping concentration increases from 0 to 1 mM in organic salt, average crystallite size of perovskite decreases monotonously from 90 to 34 nm; Surface fluctuation reduces from 259.9 to 179.8 nm at first, and then increases; Similarly, surface roughness decreases from 45.55 to 26.64 nm at first, and then rises. Accordingly, a kind of “confinement effect” is resolved to crystallite growth and surface fluctuation/roughness, which helps to build compact and uniform perovskite film. Density of trap states (t-DOS) is cut down by ≈60% at moderate doping (0.2 mM). Due to the “confinement effect”, power conversion efficiency of perovskite solar cells is improved from 19.46 (±2.80) % to 21.50 (±0.99) %, and further improved to 24.11% after surface modification. Meanwhile, “confinement effect” strengthens crystallite/grain boundaries and improves thermal stability of both film and device. T80 of device increases to 120 h, compared to 50 h for reference ones.
KW - confinement effect
KW - perovskite
KW - polyvinyl pyrrolidone (PVP)
KW - stability
KW - thermal
U2 - 10.1002/smll.202207848
DO - 10.1002/smll.202207848
M3 - Article
AN - SCOPUS:85150779196
SN - 1613-6810
JO - Small
JF - Small
ER -