1. CUÑADO, Jeaneth T. GEQUINTO, Leah Jane P. MANGARING, Meleria S. cgmarts@ee12

2. PHOTODIODE A photodiode is a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation. The common, traditional solar cell used to generate electric solar power is a large area photodiode. OPERATION A photodiode is designed to operate in reverse bias. Photoelectric effect. Photocurrent.

3. HISTORY & THEORY Photodiode technology developments came out of the basic developments of the PN junction diode that started in the 1940s in earnest. Applications for the use of the PN junction diode were found outside the basic use of rectifying signals. Photodiode technology was refined in the 1950s and in the latter part of that decade the PIN photodiode was developed. Light absorption in the wide depletion area of the PIN structure was first investigated in a paper published in 1959 by Gartner. Although silicon has been the favoured material for photodiodes, germanium can also be used, and its use was first demonstrated in 1962 by Riesz.

4. MATERIALS STRUCTURE

5. TYPES 1. PIN photodiode 2. PN photodiode 3. Avalanche photodiode 4. Schottky photodiode ADVANTAGES & DISADVANTAGES +Advantages for the Photodiode detector are high NIR sensitivity and high speed. - Disadvantages are limited amount of pixels and no UV response.

6. CHARACTERISTICS Photodiodes are similar to regular semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-rays) or packaged with a window or optical fiber connection to allow light to reach the sensitive part of the device. Many diodes designed for use specifically as a photodiode use a PIN junction rather than a p-n junction, to increase the speed of response.

7. CHARACTERISTICS