fotodiodematrix

Fotodiodematrix, or photodiode array, refers to a two-dimensional assembly of photodiodes designed to detect light with spatial resolution. Each element functions as a photodiode converting photons into electrical current or voltage. In most configurations, diodes are reverse-biased and integrated with readout electronics to produce an image or a light-intensity map.

Common implementations include active pixel sensors (APS), where each pixel contains a photodiode and an amplification transistor, and passive pixel sensors (PPS), in which photodiodes share a common readout bus. The array is scanned or read out in rows and columns to form the final data. Arrays can be linear (one-dimensional) or two-dimensional.

Silicon is the most widely used photodiode material for visible and near-ultraviolet light; other materials such as InGaAs or Ge extend sensitivity into the infrared. The spectral response, response time, dark current, and noise depend on material, device design, and temperature. Typical performance metrics include responsivity, quantum efficiency, dynamic range, and fill factor.

Applications span imaging and measurement tasks, including digital cameras, optical scanners, spectroscopy, laser line monitoring, and optical communication receivers. In research and industry, photodiode matrices are used where direct light-localization with fast response is needed, sometimes in conjunction with microlens arrays or integration with CMOS or other semiconductor technologies.

Limitations include cost, complexity, dark current, crosstalk between adjacent elements, and finite fill factor. Compared with CCD sensors, photodiode matrices in CMOS technology offer on-chip amplification and random-access readout, but trade-offs may include higher noise in some designs.