Amidine Small-Molecule Interfacial Modification Strategy in Perovskite Solar Cells

doi:10.16553/j.cnki.issn1000-985x.2025.0008

Abstract

Abstract: To passivate defects in perovskite and enhance perovskite flims quality，a novel small molecule，2-amidinoethylenediamine dihydrobromide （2AD）， was designed for interfacial modification of mixed-cation mixed-halide perovskite （（FA_0.90MA_0.05Cs_0.05） Pb（I_0.96Br_0.04）₃） flims with a bandgap of 1.55 eV. The inverted perovskite solar cells （PSCs） were fabricated via an anti-solvent method using chlorobenzene， followed by systematic analysis of phase composition， optoelectronic properties， and device performance. Experimental results demonstrate the multifunctional effectiveness of 2AD in three key aspects： 1） the grain size of perovskite films increases from 304 nm to 321 nm， accompanied by reduces surface roughness from 16.6 nm to 15.8 nm， and enhances hydrophobicity contact angle from 70.1° to 74.3°，the hydrophobicity increases； 2） the photogenerated carrier lifetime is significantly prolonged， effectively suppressing non-radiative recombination and facilitating charge transfer； 3） unencapsulated devices retains over 90% of their initial power conversion efficiency after 30 d exposure to ambient atmosphere. Finally， the efficiency of the perovskite device increases from 21.32% to 23.49%， and the hysteresis factor significantly reduces.

Key words: perovskite; solar cells; interface modification; defect passivation; stability

CLC Number:

TM914.4

WANG Zhichao, YE Linfeng, RUAN Miao, YANG Chao, JIA Xuefeng, NI Yufeng, GUO Yonggang, GAO Peng. Amidine Small-Molecule Interfacial Modification Strategy in Perovskite Solar Cells[J]. Journal of Synthetic Crystals, 2025, 54(5): 873-881.

Figures/Tables 8

Table 1 Mass of each component in perovskite

Component of PVK	FAI	MABr	CsI	PbBr₂	PbI₂	MACl
Mass/mg	232.78	7.98	19.49	28.21	675.76	30.159

Fig.1 SEM images of perovskite films with （a），（b） and without 2AD treatment （d），（e）， and grain statistics （c），（f）

Fig.2 AFM images of perovskite films without （a），（b） and with （c），（d） 2AD treatment

Fig.3 Water contact angle images of perovskite films without （a） and with （b） 2AD treatment

Fig.4 XRD patterns （a） and FWHM analysis （b） of perovskite films with and without 2AD treatment

Fig.5 UV-Vis absorption spectra （a）， band gap plots （b）， PL spectra （c）， and TRPL spectra （d） of perovskite films with and without 2AD treatment

Fig.6 XPS with and without 2AD treatment. （a） Pb 4f；（b） I 3d；（c） N 1s

Fig.7 J-V curves of perovskite devices with （a） and without （a） 2AD treatment， forward and reverse scan data， and （c） device stability

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