Regulating Perovskite Film Crystallization via Organic Amine Salts for Enhanced Photoelectric Conversion Efficiency and Stability

doi:10.15541/jim20250108

Abstract

Abstract:

Currently, photoelectric conversion efficiency (PCE) of perovskite solar cells (PSCs) has reached 27%, yet their industrialization remains constrained by film quality and stability issues in perovskite layers. This study employed butylammonium iodide (BAI) as additive to regulate crystal orientation in perovskite films through retarded crystallization kinetics and induced preferred orientation growth, resulting in significantly enlarged grain sizes and reduced defect densities. Benefiting from the intrinsic high hydrophobicity of organic ammonium salts, optimized films demonstrated enhanced environmental tolerance. Consequently, achieved PCE of rigid devices improved from 22.32% to 23.46% with notably suppressed hysteresis, while that of flexible perovskite solar cells (F-PSCs) improved from 21.51% to 22.26%, confirming the strategy's universality across substrates. Stability tests demonstrated that treatment of perovskite film with BAI led to simultaneous improvements in the environmental stability, thermal stability and light stability of PSCs, as well as the mechanical stability of F-PSCs. This work provides a novel solution for enhancing crystallization control and stability in perovskite films, offering new insights for developing high-performance perovskite photovoltaics with significant industrial application potential.

Key words: additive, perovskite solar cell, photoelectric conversion efficiency, stability

CLC Number:

O646

JIANG Jun, YANG Gonglü, YANG Yufan, LI Yi, YUAN Ningyi, DING Jianning. Regulating Perovskite Film Crystallization via Organic Amine Salts for Enhanced Photoelectric Conversion Efficiency and Stability[J]. Journal of Inorganic Materials, 2026, 41(2): 186-192.

Figures/Tables 17

Fig. 1 (a) SEM images, (b) water contact angles, and (c) AFM topographical images of xBAI-Pf (x=0, 0.068, 0.136, 0.204)

Fig. 2 (a) XRD patterns of xBAI-Pf (x=0, 0.068, 0.136, 0.204); (b, c) Semi-in situ 3D XRD patterns of (b) 0BAI-Pf and (c) 0.136BAI-Pf on different heating stages

Fig. 3 (a, b) XPS spectra, (c) Tauc plots corresponding to UV-Vis absorption spectra, (d, e) UPS spectra, and (f) schematic energy levels of 0BAI-Pf and 0.136BAI-Pf Colorful figures are available on website

Fig. 4 (a) PL spectra, (b) TRPL spectra of 0BAI-Pf and 0.136BAI-Pf; (c) SCLC spectra of devices containing two types of thin films Inset in (c): structural diagram of SCLC device. Colorful figures are available on website

Fig. 5 (a) Cross section SEM image of 0.136BAI-PSCs; (b) J-V curves of xBAI-PSC; (c) Forward (F) and reverse (R) scanning J-V curves and (d) EQE spectra of 0BAI-PSCs and 0.136BAI-PSCs; (e) Forward and reverse scanning J-V curves and (f) attenuation curves of PCE with bending cycles at a bending radius of 5 mm for 0BAI-F-PSCs and 0.136BAI-F-PSCs Inset in (e): photograph of flexible PSCs; Inset in (f): bending experiment. Colorful figures are available on website

Fig. S1 Histograms of grain size distribution of (a) 0BAI-Pf, (b) 0.068BAI-Pf, (c) 0.136BAI-Pf, and (d) 0.204BAI-Pf

Fig. S2 Peak intensity ratios of (100) to (111) crystal planes of 0BAI-Pf and 0.136BAI-Pf from XRD patterns

Fig. S3 Optical microscope images of annealing process of 0BAI-Pf and 0.136BAI-Pf

Fig. S4 Statistical plots of photoelectric performance parameters of xBAI-PSCs (a) PCE; (b) VOC; (c) FF; (d) JSC

Fig. S5 Environmental stability of 0BAI-PSCs and 0.136BAI-PSCs

Fig. S6 Thermal stability of 0BAI-PSCs and 0.136BAI-PSCs

Fig. S7 Illumination stability of 0BAI-PSCs and 0.136BAI-PSCs

Table S1 Energy level structure parameters of 0BAI-Pf and 0.136BAI-Pf

Film	E_cutoff/eV	E_Fermi/eV	E_VB/eV	E_CB/eV	E_F/eV	E_g/eV
0BAI-Pf	17.16	1.27	-5.33	-3.78	-4.06	1.55
0.136BAI-Pf	17.27	1.30	-5.25	-3.70	-3.95	1.55

Table S2 TRPL lifetime fitting parameters of 0BAI-Pf and 0.136BAI-Pf

Film	τ₁/ns	A₁	τ₂/ns	A₂	τ_ave/ns
0BAI-Pf	33.13	0.40	40.49	0.40	37.18
0.136BAI-Pf	83.67	0.36	102.27	0.36	109.80

Table S3 Photovoltaic performance parameters of xBAI-PSCs

PSCs	V_OC/V	FF/%	J_SC/(mA·cm^-2)	PCE/%
0BAI-PSCs	1.11	81.21	24.75	22.32
0.068BAI-PSCs	1.11	82.67	24.92	22.85
0.136BAI-PSCs	1.11	83.43	25.29	23.46
0.204BAI-PSCs	1.09	82.07	24.96	22.41

Table S4 Parameters of forward and backward scanning J-V curves of 0BAI-PSCs and 0.136BAI-PSCs

PSCs	V_OC/V	FF/%	J_SC/(mA·cm^-2)	PCE/%
0BAI-PSCs-R	1.11	81.21	24.75	22.32
0BAI-PSCs-F	1.11	80.91	23.70	21.29
0.136BAI-PSCs-R	1.11	83.43	25.29	23.46
0.136BAI-PSCs-F	1.11	82.97	25.09	23.07

Table S5 Parameters of J-V curves of 0BAI-F-PSCs and 0.136BAI-F-PSCs

PSCs	V_OC/V	FF/%	J_SC/(mA·cm^-2)	PCE/%
0BAI-F-PSCs-R	1.11	78.64	24.74	21.51
0BAI-F-PSCs-F	1.11	76.75	24.71	21.04
0.136BAI-F-PSCs-R	1.11	81.24	24.82	22.26
0.136BAI-F-PSCs-F	1.11	80.87	24.66	22.17

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