pspice vbe
Viren,
The best way to get your Ic & Ib vs. Vbe data is to set up your transistor test this way. Use a voltage source to apply 0V to the collector, and put a ammeter in series with it to measure the collector current. Do the same with the base, where you will apply 0V to the base and measure the base current with a ammeter. On the emitter apply a negative voltage from -0.4V and sweep it to -1.2V at 0.1V increments. For each increment of Vbe record the Ic & Ib. Once you are completed, you can plot your data, log Ic, log Ib vs. Vbe, which will be you gummel curve.
To optimize where the collector current, where it starts curving or deviating from being linear, the parameters which affect it are RB, RE, & IKF.
Good luck.
Krash