PhysicsKund Physics class 9 to 12 NCERT, JEE - NEET

Chapter 14: Semiconductor Electronics: Materials, Devices and Simple Circuits - Physics Kund 1. Classification of Metals, Conductors, Insulators and Semiconductors on the Basis of their Conductivity and Energy Bands 2. What is an Intrinsic Semiconductor? Valence Bond Theory and Energy Band Theory 3. Intrinsic Semiconductors 4. Extrinsic Semiconductors – p-type and n-type 5. p-n Junction 6. Semiconductor Diode – I-V Characteristics in Forward and Reverse Bias, Applications of Junction Diode 7. Diode as a Rectifier

Difference Between N-type Semiconductor and P- type semiconductor n-Type Semiconductors p-Type Semiconductors 1. When pentavalent impurity atoms like As, Sb etc. are added in the intrinsic semiconductor, we get n-type semiconductor. 1. When trivalent impurity atoms like gallium, indium etc. are added in the intrinsic semiconductor, we get p-type semiconductor. 2. The majority carriers in n-type semiconductor are electrons and minority carriers are holes. 2. The majority carriers in p-type semiconductor are holes and minority carriers are electrons. 3. $n_e >> n_h$ 3. $n_h >> n_e$ 4. Donor energy level lies close to conduction band. 4. Acceptor energy level lies close to the valence band. 5. Conductivity of a n-type semiconductor $\sigma_n = eN_D \mu_e$ where $N_D$ is number density of donor atom. 5. Conductivity of p-type semic...

Difference Between Intrinsic semiconductor and extrinsic semiconductor Intrinsic Semiconductors Extrinsic Semiconductors 1. Intrinsic semiconductors are the crystals of pure elements like germanium and silicon. 1. When some impurity is added in the intrinsic semiconductor, we get an extrinsic semiconductor. 2. In intrinsic semiconductor, the number density of electrons is equal to the number density of holes. i.e., $n_e = n_h$. 2. In extrinsic semiconductor, the number density of electrons is not equal to the number density of holes. i.e., $n_e \neq n_h$. 3. The electrical conductivity of intrinsic semiconductors is low. 3. The electrical conductivity of extrinsic semiconductors is high. 4. Resistivity is higher. 4. Resistivity is lower. 5. The electrical conductivity of intrinsic semi-conductors mainly depends on their temperatures. 5. Th...

What is intrinsic semiconductor , Valence Bond Theory and Energy Band Theory What is intrinsic semiconductor? Give examples. The semiconductor in which the current carriers (holes and electrons) are created due to thermal excitation only across the forbidden energy gap is called an intrinsic semiconductor  A pure semiconductor is called intrinsic semiconductor. It has thermally generated current carriers. Germanium and silicon are frequently used as intrinsic semiconductors. Explanation of Behaviour of Intrinsic Semiconductors on the Basis of Valence-Bond Theory. Structure of an intrinsic semiconductor. The three dimensional diamond like structure for Germanium or silicon or carbon is shown in figure. The lattice spacing for Germanium crystal is 5.66 A° the lattice spacing for silicon crystal is 5.43 A° and the lattice spacing for carbon crystal is 3.56 A° Each atom of silicon (Si) and germanium (Ge) has four valence electrons (i.e., electrons in its outermost shell). In a crystal ...

Classification of Metals, Conductors , Insulator and semiconductors on the basis of their conductivity and Energy Bands :  Classification of Metals, Conductors , Insulator and semiconductors on the basis of their conductivity Different solids are classified into three categories namely metals (or conductors), insulators and semiconductors on the basis of the values of their resistivity or conductivity. (i) Metallic conductor :  The substances having very low value of resistivity or very high value of conductivity are termed as metals. The order of the resistivity of metals is $10^{-2}$ to $10^{-8} \Omega$ m. Since, conductivity ($\sigma$) is inversely proportional to the resistivity ($\rho$), i.e., $\sigma = 1/\rho$, therefore, the order of conductivity of the metals is $10^{2}$ to $10^{8} \text{S m}^{-1}$. For example: silver, copper, aluminium, tungsten, mercury etc. (ii) Insulators  The solids having very high value of resistivity or very low value of conductivity are ...

Q.1 : In a n- type silicon , which of the following statements is true : (a) Electrons are majority carriers and trivalent atoms are the dopants. (b) Electrons are minority carriers and pentavalent atoms are the dopants. (c) Holes are minority carriers and pentavalent atoms are dopants। (d) Holes are majority carriers and trivalent atoms are the dopants. Solution :   An n type semiconductor is obtained by doping a pure (intrinsic) semiconductor with a pentavalent impurity. In n-type semiconductor, electrons are the majority carriers and holes are the minority carriers. Hence option (c) is true. Q.2. Which of the statement given in Q.1 is true for p-type semiconductor? Solution :  A p-type semiconductor is obtained by doping a pure (intrinsic) semiconductor with a trivalent impurity. In p-type semiconductor, holes are the majority carriers and electrons are the minority carriers. Hence option (d) is true. Q.3. Carbon , silicon and germanium have four valence electrons each. The...