김해경 (울산과학기술원)

신태주 (울산과학기술원)

김해경 (울산과학기술원)

신태주 (울산과학기술원)

김동신 (울산과학기술원)

오주연 ((주)아스타)

김태완 ((주)아스타)

진종성 (한국기초과학지원연구원)

염경문 (한국화학연구원)

전남중 (한국화학연구원)

Metal halide perovskites are promising next-generation photovoltaic materials, but their solution-processed polycrystalline thin-film nature introduces defects at surfaces, grain boundaries, and buried interfaces. Organic passivation is widely used to mitigate defect-related recombination, ion migration, and instability; however, conventional device-level and spectroscopic metrics do not readily reveal the chemical forms or spatial distributions of the introduced passivation molecules.

In this study, we investigate laser desorption/ionization time-of-flight mass spectrometry imaging (LDI-TOF-MSI) as a matrix-free analytical strategy for molecularly specific characterization of organic passivation species in perovskite solar-cell architectures. Passivated perovskite thin films were analyzed by LDI-TOF-MS, and mass spectra were reconstructed as lateral mass spectrometry images and sequential-laser-irradiation profiles. Passivator-related ions and perovskite-derived fragment/cluster ions were monitored to evaluate molecular speciation, lateral heterogeneity, and depth-correlated chemical changes near the passivation/perovskite interface.

The mass spectrometry images provide direct visualization of the spatial distribution of passivation-related signals, while sequential laser irradiation yields pseudo-depth profiles that reflect changes in molecular signals through near-surface and buried-interface regions. Because the LDI depth axis is governed by laser-shot-dependent material removal rather than calibrated sputter depth, these profiles are interpreted as depth-correlated rather than strictly quantitative depth profiles. Overall, this work demonstrates the potential of LDI-TOF-MSI as a complementary tool to TOF-SIMS for probing organic passivation chemistry and spatial heterogeneity in perovskite devices.