Unijunction Transistor (UJT) A Unijunction Transistor (UJT) is an electronic semiconductor device that has only one junction. It has three terminals an emitter (E) and two bases (B1 and B2). The base is formed by lightly doped n-type bar of silicon. Two ohmic contacts B1 and B2 are attached at its ends. The emitter is […]

BIPOLAR JUNCTION TRANSISTOR The transistor is a three-layer semiconductor device consisting of either two n- and one p-type layers of material or two p- and one n-type layers of material called an npn transistor and a pnp transistor respectively. Bipolar junction transistors are made of a semiconductor material (usually silicon) and consist of three doped

Zener Diode A Zener Diode is a special kind of diode which permits current to flow in the forward direction as normal, but will also allow it to flow in the reverse direction when the voltage is above the breakdown voltage or ‘Zener’ voltage. Zener diodes are designed so that their breakdown voltage is much

SEMICONDUCTOR DIODE (p-n junction diode)  A diode is a semiconductor device, made from a small piece of semiconductor material, such as silicon, in which half is doped as a p region and half is doped as an n region with a pn junction and depletion region in between. The p region is called the anode

SEMICONDUCTORS All materials can be classified into three major categories:  Semiconductors Some examples of semiconductor materials are Germanium (Ge), Gallium Arsenide (GaAs) and Silicon (Si). Semiconductor materials can broadly be classified into two types’ intrinsic semiconductors and extrinsic semiconductors. Intrinsic Semiconductors Intrinsic semiconductors are those semiconductors, the electron concentration is equal to the hole concentration.