Host–guest interfaces in perovskite quantum dot@MOF/COF composites: from coordination-driven passivation to extreme environmental stability

Host – guest interfaces in perovskite quantum dot@MOF/COF composites dictate the exceptional environmental and operational stability of inherently fragile metal halide perovskite quantum dots (PQDs). This review highlights how rationally designed PQD – framework interfaces convert intrinsic instability into long-term durability via coordination-driven passivation and rigid confinement. Functional groups of MOFs/COFs (carboxylate, imidazolate, thiomethyl, amine, pyridyl) directly bind under-coordinated Pb2 + sites with energies > 1.2 eV, increase halide vacancy formation energies from < 0.1 eV to > 1.4 eV, and induce compressive strain that blocks ion migration and anion exchange. Crystalline pore walls simultaneously isolate QDs by 10–20 nm, prevent solid-state diffusion, exclude moisture/oxygen, and inhibit fusion above 200°C. Resulting composites retain > 90% initial photoluminescence quantum yield after 12–18 months in ambient air (60–90% RH), > 60 days in water, and > 10 000 h of high-flux illumination – representing 3–5 orders of magnitude stability enhancement over bare PQDs. Rigid, functionalized hosts with optimized pore chemistry consistently outperform flexible or inert matrices. Key challenges in interfacial uniformity, chemical compatibility, and scalability are evaluated to guide future design of ultra-stable, interface-engineered PQD optoelectronic composites.