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Applet Tutorial

• The Stop button, the process stops.
• The Start button initiates a new process.
• The Pause/Resume button temporarily halts the process so that the data can be recorded or a momentary snap shot of the process can be examined.
• The three checkboxes, width vs. t, displcmnt vs. t, N vs. t, display the data for the width of concentration profile, the displacement of the peak from its initial position, and the total number of excess minority carriers, respectively, as a function of time for the first 100 microseconds.

Check in the applet the checkboxes of
• width vs. t,
• displcmnt. vs. t, and
• N vs. t
• Diffusion
• Set lifetime to infinity, bias to 0 V and material to p-type.

•     ===>  Start the applet, and observe the minority carriers.
• Set lifetime to infinity, bias to 0 V, material to n-type.

•     ===>  Start the applet, and observe the minority carriers.
• Set lifetime to infinity, bias to 0 V, mobility to 3900 cm2/VS.

•     ===> Start and observe.
• Drift
• Set lifetime to infinity, bias to +2V, material to p-type.

•    ===> Start the applet, and observe !
• Set lifetime to infinity, bias to +1V, material to n-type.

•    ===> Start the applet and observe !
• Set lifetime to infinity, bias to -2V, material to n-type.

•    ===> Start the applet and observe !
• Set lifetime to infinity, bias to -1V, material to p-type.

•    ===> Start the applet and observe.
• Recombination
• Set lifetime to 1ms and bias to +0V.
• Set lifetime to 0.1ms and bias to +0V.
• Set lifetime to 0.01ms and bias to +0V.

Note: Since the minority carrier lifetimes are long in Ge, as compared to Si or GaAs, the example is given for Ge. You can change the conduction type, bias value, length of the sample, temperature, lifetime, and mobility (of minority carrier) using the bottom panel and examine their effects on the excess minority carrier processes.

• A 'virtual laboratory' worksheet for this applet, created by Prof. Jennifer Ross of Univ. of Pacific, is available in pdf format. Print the form out and complete it while working with the applet. (C.Wie, 2/17/1999)