Individual solar cells and certain photovoltaic assemblies can fall within the photosensitive semiconductor heading at the SITC level, though at the HTS 10-digit level they have dedicated subheadings. Critically, solar cells and modules from several countries — including China — have been subject to antidumping and countervailing duty orders as well as Section 201 safeguard tariffs. Importers must identify the specific product type, cell technology (crystalline silicon vs. thin-film), and country of origin to determine the full duty and trade-remedy exposure before entry.

Optocouplers are composite devices, and their HTS classification is typically determined by the component that imparts the essential character or by specific HTS notes governing composite semiconductor devices. In practice, optocouplers are often classified under the photosensitive semiconductor subheadings rather than the LED or transistor headings, but the correct 10-digit HTS code depends on the device's construction and the applicable chapter notes. A CBP binding ruling is advisable for high-volume optocoupler imports to lock in the classification.