Determination of Plancks constant from the LED
Price And Quantity
Study of Plancks Constant by means of LE
Several proposals to measure the Plancks Constant for didactical purposes, using the current voltage (I V) characteristics of a light emitting diode (LED) have been made quite regularly in the last few years. The physical interpretation however is not completely clear and this has raised many discussions, which have been published almost with same regularity as the proposals themselves.
Where, e is electronic charge, k is Boltzmann constant, T is absolute temperature and h is material constant which depends on the type of diode, the location of recombination region, etc.
Dependence of current (I) on temperature (T) at constant applied voltage (V)
The following facilities are built in for this
- A highly stable current source with 3 digit display.
- Range : 0-2000A/ 20mA
- It is a small temperature controlled oven with built-in RTD sensor.
- Temperature adjustable from ambient to 80 degree celcius
- Digital display of temperature
- High stability
- Variable Voltage Source (0-2.75V)
- A high stability voltage source with 3digit display
To draw I-V characteristics of LED for determination of h, a variable voltage source and a current meter are provided with 3 digit display.
The wavelength l of light emitted by LED
These are taken from LED datasheet
- 5 Per Week
- 4-5 Days