When an electron is thermally excited to conduction band in semiconductor, an electron is surrounded by :
a large number of unoccupied energy states
Conduction band: at ordinary temperatures it is almost completely empty.
Electron concentration \(n \ll N_C\), where \(N_C \approx 2.8 \times 10^{19}\ \mathrm{cm^{-3}}\) is the effective density of states in Si.
Occupancy of a level: \(f(E) = \frac{1}{1 + e^{(E - E_F)/kT}} \ll 1\) for \(E \geq E_C\).
So the excited electron is surrounded by many empty states into which it can move freely under an applied field.
Hence, a large number of unoccupied energy states.
Similar Questions
How does an LCD pixel control the passage of light to create different colors ?
In a Zener diode, what is the primary role of the depletion region ?
In semiconductor manufacturing, what does the term wafer refer to ?
In the semiconductors, what is the role of a doping ?
What is the primary role of barrier layers in quantum well devices ?
What is the unique structural feature of a carbon nanotube that contributes to its exceptional strength ?
What is the primary advantage of LED technology over traditional incandescent lighting ?
What are potential applications of ZnO in the field of optoelectronics ?
In the I-V curve of a solar cell, what does the open-circuit voltage (Voc) represent ?
A sharp peak in a X-Ray Diffractogram represents :
Important Questions from Mixed Topic (MH-SET)
.................... is a client server application that identifies each host on the internet with a unique user-friendly name.
Every OS has a ................ or .......... which primarily resides in the main memory of the computer to perform some of the basic functions of the OS.
(i) Kernel
(ii) Interface
(iii) Nucleus
(iv) Compiler
Codes:
Which of the following are referred to as low level language?
(i) Machine language
(ii) Assembly language
(iii) High level language
(iv) Natural language
Codes:
Match the following:
List I List II (a) New York Public Library (i) Shelv AR (b) Miami University Augmented Research Group (ii) Smart library (c) Oula University Library (iii) Wolf Walk (d) North Carolina State University (iv) Find the future Codes:
Which part of the QR code represents the encoded data?
