photodriven

Photodriven describes processes, reactions, and phenomena that are powered, initiated, or controlled by light. In science, the term highlights the role of photon absorption in generating excited electronic states, charge carriers, or thermal effects that drive chemical transformations, mechanical motion, or structural changes. It is used across chemistry, materials science, physics, and biology to distinguish light-powered from thermally driven phenomena.

In chemistry and materials science, photodriven mechanisms include photoinduced electron transfer, energy transfer, and photocatalysis. Photoexcitation can produce reactive species or charge separation that enables redox reactions, bond formation, or degradation of pollutants. Photocatalysis, using light-activated catalysts, aims to facilitate reactions such as water splitting or carbon dioxide reduction, often under solar or visible illumination. Photoresponsive materials rely on light to alter properties or reactivity, enabling switching, self-assembly, or actuation.

In biology and soft matter, photodriven systems encompass light-activated motors, photoisomerization of molecular switches, and photoresponsive polymers that change conformation or stiffness in response to light. Such mechanisms enable controlled motion, assembly, or release at micro- to mesoscale levels, with applications in targeted drug delivery and smart materials.

In physics and energy science, photodriven processes underpin the operation of solar cells, photodetectors, and photovoltaic devices. Photothermal and photomechanical effects—where light converts to heat or mechanical work—also enable actuation and energy transduction without electrical input.

Advantages of photodriven approaches include rapid, reversible, and spatially selective control. Limitations often involve material stability, limited light absorption, and energy losses during transfer or conversion. See also photochemistry, photocatalysis, photoresponsive materials, and photothermal effects.