Please I want to purchase infrared led ( transmitter ) and phototransistor ( reciever ) ,but I am not sure if they are matched ,could anyone give me links of ir led and phototransistor that are matched.
The IR emitter is tuned to output 950nm and the receiver is tuned to best detect at 950 nm. Be careful on the receiver, though it is very simple, you have to make sure that your emitter is putting out the right carrier frequency. This is to reduce spurious signals from other light sources. The info is in the datasheet and is very clear, just make sure you read it.