lightresistance

Lightresistance is a term used in multiple disciplines to describe how a system opposes or responds to incident light. In optics, it refers to the attenuation or reflection of light by a material. In electronics and photonics, it can describe how a material's electrical resistance changes under illumination, a phenomenon known as photoconductivity.

In optics and materials science, lightresistance corresponds to optical resistance to transmission: high absorbance, scattering, or reflection results in low transmittance. The relevant properties include the absorption coefficient, extinction coefficient, refractive index, and reflectivity. Opaque or highly reflective surfaces exhibit high lightresistance to transmission.

In photoconductive contexts, lightresistance is the change in electrical resistance caused by illumination. Many semiconductors decrease resistance when illuminated due to generated charge carriers. This is exploited in devices such as photoresistors (LDRs), photodiodes, and photovoltaic cells.

Materials and devices are characterized by measurements of R under dark and light conditions, spectral response, and responsivity. Common examples include CdS and CdSe-based photoresistors, silicon photodiodes, and organic semiconductor composites.

The term is not standard across disciplines and may be used loosely to describe either optical attenuation or photoresponse phenomena. In literature, specific terms such as transmittance, reflectance, absorbance, attenuation coefficient, or photoconductivity are preferred.