Klinger Scientific Photoconductivity Experiment Set Up

Photoconductivity utilises absorption of light by means of the inherent photoelectric effect in a semiconductor to create electron-hole pairs. One specific semiconductor mix which exhibits the photoelectric effect particularly strongly is cadmium sulphide. This material is used in the construction of photoresistors. In this experiment, a CdS photoresistor is illuminated with white light from an incandescent bulb. The intensity of this illumination of the photoresistor is then varied by crossing two polarising filters placed one behind the other in the beam.

Objectives

• To study the photoconductivity of CdS Photoresistor, in the following conditions:
• Applied voltage vs photocurrent (IPH) at constant irradiance (Φ).
• Photocurrent (IPH) vs irradiance (Φ) at constant applied voltage (V).
  Principle
  The phenomenon of photoconductivity occurs when an incident light shown upon a semiconductor causes an increase in its electrical conductivity. This is because of excitation of electrons across the energy gap into the conduction band, which leads to an increase in the number of free carriers in the conduction band, hence, an increase in the conductivity of the semiconductor. Here, we can study the characteristics of the CdS photoresistor under different conditions of light intensity and applied voltage.

KEY FEATURES

• Precise Optical Alignment: The optical alignment of the components is attained by optical bench, the setting up time is faster and experimentation is easy.
• Fine and Easy Light Intensity Adjustment: Light intensity adjustment is done via use of two polarizers. This helps in easier and fine light intensity adjustments.
• Simple and Easy Connections: The color-coded terminals on the various components aids in the ease of connections thus reducing the setup time.

WHAT YOU NEED

• KSCIOB2 Optical Bench Set 0.4m 1
• KSCIHA001 Light Source Holder 1
• KSCIHA004 Polarizer Holder 1
• KSCIHA006 Analyzer Holder 1
• KSCIHA020 LDR Module Holder 1
• KSCIPS61022D/20 Power Supply, 0-15V, 200mA 1
• KSPS61022D/2 Power Supply for Light Source 1
• KSCIPCE : Complete Equipment Set With Instruction Manual

INSTRUCTIONS FOR USE CLICK HERE