Photovoltaic Detector
Definition and meaning of Photovoltaic Detector in chemistry.
A photovoltaic detector is a sensor that converts incident radiant energy directly into an electrical current or voltage.
In more detail
These analytical devices typically rely on semiconductor materials constructed with a p-n junction. When photons with sufficient energy strike the active surface of the detector, they excite electrons from the valence band into the conduction band, creating mobile electron-hole pairs. The built-in electric field at the semiconductor junction separates these charge carriers before they can recombine. This separation results in a measurable photocurrent that is directly proportional to the intensity of the incident light striking the sensor.
Key facts
| Field | Analytical Chemistry |
|---|---|
| Mechanism | Generation of electron-hole pairs |
| Formula Example | Si |
A silicon photodiode used as the primary detector in a laboratory UV-Vis spectrophotometer to measure the intensity of light passing through a chemical sample is a common type of photovoltaic detector.
Frequently asked questions
What is the difference between a photovoltaic and a photoconductive detector?
A photovoltaic detector generates its own voltage when illuminated, while a photoconductive detector requires an external power source to measure changes in resistance.
What materials are commonly used?
Silicon and gallium arsenide are frequently used due to their semiconductor properties.