Determination of Impurities in Photovoltaic-Grade Sb2Se3 for Solar Cells Using Inductively Coupled Plasma Tandem Mass Spectrometry

Antimony selenide (Sb2Se3) is an emerging absorber material for thin-film photovoltaics due to its suitable bandgap, strong light absorption, and environmental stability. However, the performance of Sb2Se3 solar cell device remains constrained by deep-level traps, which primarily originate from trace impurities in Sb2Se3 that induce local lattice distortions and promote non-radiative recombination. In this study, inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was employed to accurately determine impurity elements in photovoltaic-grade Sb2Se3. In the MS/MS mode, An N2O/H2 mixture was used as the reaction gas to eliminate spectral interference, the on-mass method was adopted to quantify Na, K, Ni, Cu, Cd, Te, and Bi, and the mass-shift method was used to quantify S, Cl, Ti, Fe, and As. The major interferences on analytes were eliminated. The optimal flow rates of N2O and H2 in the octopole reaction system (ORS) were determined to be 0.22 and 7.0 mL min^-1, respectively. The limits of detection (LODs) for the analytes ranged from 0.05 to 41.80 ng L^-1, the spiked recoveries of Sb2Se3 samples ranged from 95.6% to 106%, and the relative standard deviation (RSD) was in the range of 3.1%-6.1%. No significant differences were observed between the analysis results of the developed method and those obtained using sector field (SF) ICP-MS at a 95% confidence level. This work provides an effective strategy for impurity profiling in photovoltaic-grade Sb2Se3, which may be extended to other high-purity semiconductor materials.