Overview

This apparatus designed a micro current power supply to be used as the forward current of the PN junction. By adjusting the micro current to obtain the forward voltage drop across the PN junction, this can effectively avoid the instability of the measured micro current and accurately measure the forward voltage drop. A temperature control device is designed to obtain the volt-ampere characteristic curve of the PN junction at different temperatures, and the relationship between the PN junction voltage, current and temperature is studied, from which the Boltzmann constant k, the sensitivity S and the forbidden bandwidth of the silicon material are obtained.

Principle

The physical properties of semiconductor PN junctions are an important foundation of semiconductor physics. Using this apparatus, the relationship between the PN junction diffusion current and the voltage can be studied. Students can also learn that this relationship follows the exponential distribution law, and the physics important constant, the Boltzmann constant, can be measured accurately.

At the mean time, the relationship between the PN junction voltage and the thermodynamic temperature can also be measured. With thisrelationship, students can get the sensitivity S of the temperature sensor which made by PN junction. Further, the temperature 0 K's forbidden bandwidth of the silicon material can be obtained approximately.

Experiments and Typical Results

1. Measure the IF - Ube curve at room temperature

2. Measure the Ube - T curve

The results obtained by digital experiment

Parts List

BEM-5714    PN Junction Characteristic & Boltzmann Constant Controller

BEM-5051    Temperature Control Power Supply II

BEM-5052    PN Junction Heating Device

BEM-5053    PN Junction Probe

Options

UI-5001    550 universal data acquisition interface

UI-5400    Capstone data acquisition software

PS-3211    Wireless voltage sensor (2)

Packinglist

Apparatus x 1; Power cord x 2; Connection cable x 5; Sheathed banana plug cable x 2; Manual x1