• Photodiode is a 2 lead semiconductor device that transforms light energy to electric current.
• Suppose anode and cathode of a photodiode are wired to a current meter.
– When photodiode is placed in dark, the current meter displays zero current flow.
– When the photodiode is expose to light, it acts a a current source, causing current flow from cathode to anode of photodiode through the current meter.
• Photodiodes have very linear light v/s current characteristics.
– Commonly used as light meters in cameras.
• Photodiodes often have built-in lenses and optical filters.
• Response time of a photodiode slows with increasing surface area.
• Photodiodes are more sensitive than photoresistor.
• Suppose anode and cathode of a photodiode are wired to a current meter.
– When photodiode is placed in dark, the current meter displays zero current flow.
– When the photodiode is expose to light, it acts a a current source, causing current flow from cathode to anode of photodiode through the current meter.
• Photodiodes have very linear light v/s current characteristics.
– Commonly used as light meters in cameras.
• Photodiodes often have built-in lenses and optical filters.
• Response time of a photodiode slows with increasing surface area.
• Photodiodes are more sensitive than photoresistor.
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