Automated Multimodal Mapping of Optical and Relative Surface-Potential Responses in a FAPbI3–BDAPbI4–PEA2PbI4 Halide Perovskite Library
Year: 2026
Type: preprint
Abstract: High-throughput (HT) characterization has accelerated materials screening, however most workflows for functional characterization rely on a single measurement modality. This approach leaves the relationship between different aspects of materials response, such as optical emission and local electronic behavior, largely unassessed within the same campaign. Multimodal characterization, particularly pairing probe-based electronic measurements with optical screening, remained comparatively underdeveloped. Here we address this gap by combining automated Kelvin probe force microscopy under illumination (photoKPFM) with HT photoluminescence (PL) peak-intensity mapping to screen a formamidinium lead iodide (FAPbI3), 1,4-butanediammonium lead iodide (BDAPbI4), and phenethylammonium lead iodide (PEA2PbI4) combinatorial halide perovskite library. A Gaussian-process Bayesian optimization with pure exploration workflow selects photoKPFM measurements to reconstruct the composition-dependent surface potential response, benchmarked on a binary FAPbI3–PEA2PbI4 line before extension to the ternary system. Comparing photoKPFM against PL peak intensity across 13 unique nominal ternary compositions, measured on independently prepared replicate libraries, shows that both descriptors broadly prioritize PEA2PbI4-rich compositions, but individual composition rankings frequently disagree, and exploratory correlation analysis finds no statistically significant global association between the two measurements after multiple-comparison correction. Rather than indicating redundancy, this divergence shows that photoKPFM and PL provide complementary, non-interchangeable candidate-selection information, jointly identifying compositions that rank consistently strong by both descriptors and compositions whose priority depends on which functional descriptor is used. This work demonstrates how pairing automated probe-based and optical HT methods surfaces candidates that single-modality screening would rank differently, motivating multimodal characterization as a general, extensible strategy for combinatorial materials discovery beyond this specific material system.
Source: ChemRxiv
Institution: University of Tennessee at Knoxville
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204817636