Mechanism of abnormal cellular growth in CVD-ZnS under multifactorial coupling effects and its hierarchical suppression strategies

Chemical vapor deposition (CVD)-synthesized zinc sulfide (ZnS) is a key material for high-performance infrared optical systems. However, the process is prone to Abnormal Cellular Growth defects, which compromise material uniformity and optical performance. This study systematically investigates the formation mechanism and suppression pathways of Abnormal Cellular Growth in CVD ZnS through multiscale experimental analysis and theoretical modeling. Experiments employed high-purity zinc and hydrogen sulfide reacting in a graphite deposition chamber to produce polycrystalline ZnS, followed by hot isostatic pressing (HIP) post-treatment. Results indicate that Abnormal Cellular Growth is primarily driven by interface instability, influenced by temperature gradients, solute segregation, and interfacial energy coupling. Temperature non-uniformity within the deposition chamber and high deposition rates exacerbate solute enrichment, inducing cellular structures. The study further proposes a three-tiered synergistic control strategy—“root-cause prevention, process regulation, and end-of-line treatment”—significantly suppressing defect generation by optimizing substrate conditions, purifying the gas phase environment, and adjusting process parameters and post-treatment. The resulting material exhibits over 70% transmittance in the visible-infrared spectrum with markedly enhanced reliability. This research provides a theoretical framework and practical process pathway for understanding and controlling anomalous CVD ZnS growth, holding significant value for advancing the fabrication of high-performance infrared materials.