photomaterials

Photomaterials are materials designed to interact with light in ways that produce or modulate optical energy. They encompass substances that convert light into electrical energy (photovoltaics), emit light (phosphors, LEDs, lasers), rapidly respond to light with changes in optical properties (photochromic and photoresponsive materials), or catalyze chemical reactions upon illumination (photocatalysts). The field covers inorganic, organic, and hybrid systems used across energy, sensing, imaging, and information technologies.

Common classes of photomaterials include semiconductor absorbers for solar cells (such as silicon, cadmium telluride, copper indium gallium selenide, and lead halide perovskites), photodetectors, and light-emitting materials (quantum dots, organic LEDs, inorganic phosphors). Photochromic materials change color reversibly under light, enabling smart coatings and data storage. Photocatalysts, notably titanium dioxide and related oxides, use light to drive chemical reactions, including pollutant degradation and water splitting. Organic and polymeric photomaterials offer solution-processable options, while nanoscale materials such as quantum dots provide size-tunable optical properties.

Key physical concepts include band gap and absorption spectrum, charge-carrier generation and transport, quantum efficiency, exciton dynamics, and material stability under illumination. Performance depends on composition, structure, interfaces, and processing, with ongoing work to improve efficiency, longevity, and environmental compatibility.

Applications span energy conversion (solar cells and light harvesters), sensing and imaging (photodetectors and fluorescence-based probes), display and lighting technologies, optical data storage, and photocatalytic water treatment. Challenges include achieving high efficiency with long-term stability, reducing cost, and addressing toxicity and environmental impact in some material systems.