Which Advanced Materials categories face the tightest supply and strongest price upside in China?

Which Advanced Materials categories face the tightest supply and strongest price upside in China?
Several Advanced Materials segments show structural shortages rather than cyclical tightness. High-purity metals such as rhodium, hafnium, tantalum and tellurium have no independent mines, so supply depends on byproduct recovery and cannot expand quickly. Electronic-grade materials like ArF dry photoresist, ABF build-up film and high-purity silica powder remain heavily import-reliant with low domestic substitution. Indium phosphide substrates and thin-film lithium niobate wafers carry large gaps as AI optical and power devices scale. Meanwhile PPO, PEEK and ultra-high molecular weight polyethylene show the opposite pattern: capacity is arriving faster than demand, pressuring utilization and pricing.