China Wholesale Hall Effect Factories – LEEM-15 Experimental Apparatus of PN Junction Characteristics – Labor

Introduction

The physical properties of semiconductor PN junction are one of the important basic contents of physics and electronics. This apparatus uses the physical experiment method to measure the relation between the diffusion current of PN junction and voltage, proves that this relation follows the exponential distribution law, and measures the Boltzmann constant (one of the important constants in physics) more precisely, which enables the students to learn a new method to measure the weak current. This apparatus provides a heater alternating temperature thermostat to measure the relation between PN junction voltage  and thermodynamic temperature T, so as to obtain the sensitivity of the sensor, and approximate to obtain the energy gap of silicon material at 0K. This apparatus is stable and reliable, and has abundant physical experiment contents, clear concept, reasonable structural design and high-accuracy measurement results. This apparatus is mainly used in general physical experiments and design research experiments in colleges and universities.

Experiments

1. The relation between the PN junction diffusion current and the junction voltage is measured, and this relation shall be proved to follow the exponential distribution law through data processing;

2. The Boltzmann constant is measured more accurately(The error shall be less than 2%);

3. Learn to use operational amplifier to form a current-voltage converter to measure the weak current from 10^-6A to 10^-8A;

4. The relation between PN junction voltage  and temperature is measured and the sensitivity of junction voltage with temperature is calculated;

5. Approximate to calculate the energy gap of the semiconductor (silicon) material at 0K.

Technical Indexes

1. DC power supply

An adjustable 0-1.5V DC power supply;

An adjustable 1mA-3mA DC power supply.

2. LCD measurement module

LCD resolution ratio: 128×64 pixels

Two digital indicators of voltage Range: 0-4095mV, Resolution ratio: 1mV

Range: 0-40.95V, Resolution ratio: 0.01V

3. Experimental device

It is composed of operational amplifier LF356, connector socket, multi-turn potentiometer, etc. TIP31 and type 9013 triode are externally connected.

4. Heater

Dry well copper adjustable heater;

Temperature control range of thermostat: Room temperature to 80.0℃;

Resolution ratio of temperature control 0.1℃.

5. Temperature measuring equipment

DS18B20 digital temperature sensor