Most generally a class of materials that are neither insulators or conductors in their natural state but which can be manipulated via doping or electric fields to change the conduction state. Silicon, Germanium, GaAs are some usual materials. The term is also used to speak about devices that are ...

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19
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9answers
1k views

Why is the temperature range of industrial and military products so high?

From Wikipedia the common temperature range for electrical components is: Commercial: 0 to 70 °C Industrial: -40 to 85 °C Military: -55 to 125 °C I can understand the lower part (-40°C and -55°C) ...
0
votes
0answers
56 views

Electroluminescent materials - why does thickness matter?

I've been reading a lot about electroluminescent materials lately, and almost all examples I've read take the form of a conductive layer, some kind of semiconductor layer, a sometimes-absent ...
0
votes
0answers
25 views

semiconductor device modeling [closed]

in FDSOI NMOS,the channel is to be made of metallic conductor .since the process of accumulation,depletion and inversion need not nescessarily to take place.whether this will eliminate the threshold ...
-3
votes
0answers
42 views

Diode Circuit analysis [closed]

how can i solve circuits like this ?! how current flow though determine the diode modes and calculate V and current in branches
0
votes
1answer
38 views

Extrinsic semiconductors: why can't electrons/holes in the band gap conduct?

Normally, no electron energy states exist in the band gap, the gap between the valence band and conduction band in a semiconductor. However, if we dope the semiconductor, i.e. add donor (n type) or ...
1
vote
1answer
30 views

Generation Rate and Recombination Coefficient for Intrinsic Semiconductors

Generation Rate In an intrinsic semiconductor, the generation rate due to thermal energy is often given as $$G_{th} \propto \exp \left( - \frac{E_G}{k \cdot T} \right), \tag{1}\label{1}$$ with the ...
1
vote
2answers
56 views

What are “Bulk” conditions in a semiconductor?

What is meant by "Bulk condition" in a semiconductor?
0
votes
1answer
40 views

Uses of Electronic Filters? [closed]

Can anyone tell the real life examples of electronic filters? Why do we need them ? Whey do we need certain range of frequencies while others are rejected ? Sorry i am new in electronics so please do ...
0
votes
2answers
151 views

Voltage drop across a diode [closed]

For the sake of simplicity, the voltage drop across a diode, \$V_d\$ made of silicon is assumed to be \$0.7\mathrm{V}\$ after the input voltage exceeds this voltage; and \$V_d\$ is assumed to stay ...
0
votes
2answers
43 views

Understanding id-Ugs and id-Uds graph of a nMOSFET

I'm so sorry posting such a horrible-looking picture, but I really cannot found pictures similar to it online and/or in English! If you found one, please let me know and I'll replace it immediately! ...
3
votes
1answer
37 views

Why does a triac trigger with gate current in either direction?

I've been coming up to speed on thyristors, and triacs in particular. I've found detailed material on them a little hard to find, in particular on the device physics. Horowitz & Hill is silent on ...
0
votes
1answer
52 views

Efficiency of a centre tap full wave rectifier(qualitative analysis)

In a centre tap full wave rectifier the output voltage is half of the input(secondary coils voltage) voltage, so the power is half of power of secondary. Also in half wave rectifier the only half of ...
0
votes
1answer
29 views

How diffusion constant vary with temperature in Semiconductors?

Diffusion constant = Mobility*Thermal Voltage *Where,Thermal voltage = T/11600* From above equation it is clear that Diffusion constant should ...
0
votes
0answers
39 views

Is source of input signal is connected in series?

If a small sinusoidal voltage with amplitude \$v_i\$ is superposed on the dc base bias by connecting the source of that signal in series with the \$V_{BB}\$ supply, then the base current will have ...
1
vote
2answers
86 views

Variation of voltage gain with frequency

For a transistor amplifier, the voltage gain (a) remains constant for all frequencies. (b) is high at high and low frequencies and constant in the middle frequency range. (c) is ...
0
votes
1answer
50 views

Does input signal mean same as input in transistors as amplifier?

During solving [this question] I came across a term input signal, I want to know whether input signal means the input voltage or change in input voltage? I am unable to solve if I take input signal as ...
1
vote
1answer
48 views

What is meant by dc drop?

What is the exact meaning of the term dc drop in transistors? In solving the problem in the image given below , I was asked to find the dc drop across the collector resistance as shown in circuit so ...
-2
votes
1answer
31 views

What is Minority Carrier Storage Time?

I know that Minority Carrier Life-Time is the time difference Between generation of minority carrier & their Recombination. I am bit Confused Between Minority Carrier Storage Time & Minority ...
0
votes
0answers
32 views

Problem about semiconductors

This is a question from our homework What I have thought of so for goes like this: There is no optical generation for x>0, and since there is no electric field, there is no drift current (only ...
0
votes
1answer
84 views

What are the “Blind spot”s of the EM model?

I saw this sentence from one of @Dave's excellent answers: If the collector is open-circuit, all of this current flows out the base connection. But as long as there's at least a small positive ...
3
votes
2answers
83 views

Does the N material need to be directly touching the P material?

I know a diode works like: anode wire --[ P ][ N ]-- cathode wire Would it also work like so? ...
-7
votes
2answers
91 views

What alternative materials (Non-silicon) are available for semiconductors?

I'm trying to construct a simple logic gate with a transistor, but I don't want to use silicon as the semiconductor. What other materials are available to construct transistors with? Thanks for your ...
1
vote
3answers
128 views

Why Collector-to-Base currents ratio in a BJT transistor is always greater than 1?

In fact, this question has been asked on the EE site, but it's not well-answered. I suppose it might be more on-topic here. According to this answer: Note that the holes injected into Emitter are ...
2
votes
1answer
30 views

Steps to calculate the band profile of a complex semiconductor heterostructure

I am an EE undergraduate with a lot of interest in semiconductors. I took an introductory semiconductors course which was helpful but left me with some holes in my understanding, as the course ...
0
votes
1answer
72 views

Comparing sensitivity to temperature changes of BJT (transistor) circuits in Common Emitter Configuration

I measured Ic variation with Ib when Vce = 15v kept constant for BJT (NPN) in Common Emitter config and also BJT Common Emitter config with series 47 Ohm resistor connected. From the experiment I ...
3
votes
1answer
67 views

Memory Power Supply

Kindly any one give the clarification on this. While going through a DDR Memory data sheet, I have found two (more than that) power supply pins. What is the necessity of this DLL power supply ...
1
vote
2answers
98 views

Can we find potential difference of a P-N junction by connecting voltmeter?

Can we find potential difference of a P-N junction by connecting voltmeter across diode terminals? I know the answer is no but i don't know how.
0
votes
0answers
35 views

Where does this effective field come from? Semiconductors

I'm having trouble with this question. I've had a look around but I can't seem to find the answer. Any ideas? Is this something that is specific to each graph or is it just always one of the ...
0
votes
1answer
40 views

Semiconductor Doping Question

The question says: Calculate the minority carrier life-time in Si having a donor concentration, NA = 1014 cm-3 if the diffusion length for minority carriers is 150 m. Shouldnt it say "ND=1014"? ...
3
votes
1answer
240 views

Working of miniature Tesla coil?

Can anyone explain the given circuit. I seem to have done it and its perfectly working. But can someone explain the principle/theory and working behind this circuit from when the switch is turned on.. ...
-1
votes
2answers
65 views

Analogy in combination of batteries in series and pn junction diode circuit to find potential difference

Can I use the analogy of combination of two batteries to get the potential difference between two points in case a pn junction diode is used in the case of other battery? In doing so what is the basic ...
0
votes
1answer
153 views

Why is the Collector current of a BJT transistor independent of the Collector Base voltage?

Ignoring the modulation of the effective base width, why is the collector current independent of the reverse bias voltage across the Base-Collector P-N junction? On one hand, it is easy to see that ...
3
votes
3answers
102 views

LED typical and forward voltages

So, I was going through the spec sheet of super bright 5mm orange LED, and it was listed that the forward voltage is between 1.8V and 2.5V. Below that there was a property listed as 'typical voltage' ...
-1
votes
1answer
73 views

At any given semiconductor node, how many fabs in the world? [closed]

Let's pick a node, say 45nm. How many wafer fabs are there worldwide that can produce chips with that resolution? Tens? Hundreds? And does this mean that producing equipment for them is almost a ...
2
votes
1answer
134 views

Why does the MOSFET drain current increase abruptly when Gate voltage is greater than the threshold voltage?

As far I've understood, channel formation takes place because of the induced negative charge on the semiconductor side of the gate capacitance. So shouldn't the charge concentration increase linearly ...
0
votes
1answer
83 views

Inter die vs Intra die process variation

Due to fabrication process, there will be variations, among wafers as well as among dies across a wafer. My question is that what variations are significant between dies? And what variations are ...
1
vote
0answers
26 views

What does the channel voltage in a MOSFET really mean and how does it lead to the Fermi level splitting shown?

Many books (Chenming-Hu Ch.6 Page 15, Neamen Page 413) use the term 'channel voltage' \$V(y)\$ to mean 'the potential in the inverted channel at a point \$y\$ distance away from the source along the ...
5
votes
1answer
394 views

Why do electrons move faster than holes in a semiconductor?

When an electron leaves, then only a hole is created, and when another electron fills it, then only the hole moves, so in that way, both should conduct current at the same speed. Yet I've been told ...
2
votes
1answer
60 views

How to design Digital logic gate using TFET logic?

In my recent project, I need to design digital logic gates using TFET instead of CMOS logic. Can someone Suggest any simulator or procedure which support design using TFET logic?
0
votes
2answers
53 views

Current limit and current gain bjt question

Contact potential of Vbe in Q2=Vbe-on I worked out that the maximum current that can go through R2 is Vbe-on/R2. So my question is why does Q2 turn on when the emitter current of Q1 reaches this ...
2
votes
1answer
102 views

Why doesn't the gate voltage drop entirely across the oxide in a MOS capacitor?

As the title says, for a MOSCap with, say, a p-doped semiconductor substrate, when a gate voltage \$V_{g}\$ is applied across the gate and the grounded substrate, why doesn't \$V_{g}\$ drop entirely ...
1
vote
3answers
91 views

How does a forward biased diode conduct electricity?

I am having a hard time imagining the flow of current through the p-n junction. When a diode is forward biased, the holes on one side of the barrier and electrons from the other side try to cross the ...
1
vote
2answers
60 views

Quick junction / pn junction diode clarification

I was studying diodes. I was at the part where we talk about P-N junctions diodes. There is a part I am confused about. Is the "junction" part the part in the middle which blocks the current if no ...
0
votes
1answer
44 views

Semiconductor Condution

I've read that semiconductors (i.g. intrinsic silicon) behave as insulators at absolute zero (since all valance electrons are shared via neighboring atoms). My question is, does conduction still take ...
0
votes
1answer
60 views

Self Heating of LED

I am using Red LED connected to B2902A SMU which can display current Voltage curve only.But i need to find out what is the temperature(Self heating) and how to find it using I/V curve.So that i can ...
1
vote
0answers
59 views

Semiconductor Level Genetic Programming

I was reading a most likely old article about, Adrian Thompsons work on using genetic programming to generate circuit solutions for simple tasks such as frequency differentiation. This got me ...
3
votes
1answer
112 views

How do wires connect to transistors?

So I was looking at the schematic of NPN and PNP transistors which basically involved layered blocks of doped material stacked. My question is how do wires connect to these devices? I think this ...
0
votes
1answer
54 views

Semiconductor thermal equilibrium [closed]

What precisely thermal equilibrium implies in case of a semiconductor. One thing I know is that Fermi Level remains the same. But what other things does this implies, is there net current flow in case ...
0
votes
1answer
222 views

How can computer replace PLC in industrial machines? [closed]

I am having internship in a semiconductor manufacturing company and learning about machines in front-end section. Technicians say that the machines all use computers as they process multiple complex ...
3
votes
3answers
109 views

Is there an electronic device that stays “on” until the current through the device reaches a certain level?

I have the vague recollection that a device like this exists. The device is gated on, after which it approximates a short circuit, until the current through the device rises to a set level, at which ...