Composition and Temperature dependence of LEDs - 550 Words

Composition and Temperature dependence of LEDs (Research Paper Sample) Content: Name:Instructor:Course:Date:Composition and Temperature dependence of LEDsIntroductionA light-emitting diode is a semiconductor device that emits light. The LED is made up of a variety of chip of semi-conductor materials which are being doped with impurities in order to come up with a p-n junction .most diodes allows current to flows smoothly from the side p which is anode flowing then to side of n which is cathode although they does not allow the reverse way flow of current. The carrier of the charge is both, electrons and holes, flow into the junction from electrodes with different voltages. When an electron meets a hole, it falls into a lower energy level and releases energy in the form of a photon. When light - emitting diodes switched on, electrons recombine with the holes in the device and release energy in form of light in a process called electroluminescence. The type of light emitted by LEDs depends on the energy band gap of the semiconductor. When properly d esigned, the efficiency of an LED will approach 80% meaning that 80% of electrical energy will be converted to photons.( Robert K,1991).The aim of this experiment is to measure V1 and V2 which will be used to calculate the conductivity of the diode.Experiment procedure:List of materials * A voltmeter to measure the resistance of the silicon diode as the temperature of the heat sink decreases. * A silicon diode in a protective Pyrex sleeve connected to a 9 V battery * An aluminum block that will be heated and act as a heat sink * A thermometer to monitor and record the temperature of the silicon diodeProcedureStep1 : Emission spectra for the LEDs at room temperature. 1 Make sure that you open the SpectraSuite program and ensure that the LED provided ...