Learning material for understanding how photodiodes work and how to use them

[Daniel404]

I want to understand the workings of a photo diode. I already know elctromagnetism and basic circuits and electornics. Do i need a modern physics book? Please refer books or goo learning material.

 

[BradtheRad]

I took an infrared photodiode and ground away the dark-colored plastic casing. I started to expose what looked like a small photovoltaic cell. Shiny blue brushed silicon appearance. About 1/8 inch square.

A photodiode creates a voltage when light falls on it. Response is quick.
The weak signal needs to be amplified. Most schematics have it connected across the inputs of an op amp.
Of course you can try other configurations.

 

[KlausST]

Hi,

A photodiode creates a voltage when light falls on it.

... and it creates current. A TIA keeps voltage zero, just "measures" the current.
And that's the benefit of TIA. Regarding speed it cancels out photodiode capacitance (which might be rather big).
No voltage move --> no capacitive current --> no RC delay (time constant).

Klaus

 

[biff44]

there is not much to them, to the first order.
You have a lightly doped semiconductor region. Photons hit this region, and dislodge electrons. IF there is a DC voltage across the diode, that sets up a DC current as those electrons travel to the Positive lead.

If there is no external field, those electrons eventually recombine.