# All Questions

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### How does the $I$-$V$ curve for bulk metal look like?

For semiconductors, the current (I) vs. voltage (V) relationship is as shown in the picture below. As we increase the applied voltage, the electron-hole pairs generate increases too, so we see an ...
62 views

### An ohmic contact

It is claimed that Schottky type of contact between low work function p-type semiconductor and higher work function metal creates an ohmic contact in which current can flow both sides almost fluently ...
18 views

### Can I consider electron scattering with grain boundaries in metal as a tunneling process?

I am reading about the Mayadas-Shatzkes model (MS model). when electrons are scattered with the grain boundary, there is a probability that it will be transmitted to the other side of the grain ...
29 views

### Resolve The Envelope Detector Circuit

I was working on a little project and I was wondering if the envelope detector circuit could be resolved analytically. Let me explain. The circuit is the one shown above, I know the values of $C$, $R$...
110 views

### What does it mean if the resistance of a semiconductor increases due to light?

I have synthesized an $n$-type semiconductor material $\text{ZnO}$. Under light illumination, its resistance keeps increasing. What are the reasons for this?
38 views

### How do I calculate the electrical conductivty of arbitrary semi-metal?

Assume that I have an Hamiltonian $$H=\sum_{k,\sigma}a^\dagger_k E(k)a_k$$ where $E$ is the dispersion relation with gap closing at some points. I want to calculate the conductivity of this system. To ...
64 views

### Circuit Analysis - Grounding and Current

Just starting to learn basic concepts of electronics, and I'm a bit confused looking at this diagram. Previously, we've always had a wire connected to the negative end of the terminal, and that made ...
46 views

### Help with $I$-$V$ Characteristic of a Diode

I am struggling to understand why I can't get a full voltage range when I have the diode the correct way round. If you check this link: https://electronics.stackexchange.com/q/266201/ If you look at ...
8k views

### Why in a conductor increase in temperature makes the atoms vibrate but in a semiconductor the kinetic energy of the free electrons is increased?

When temperature is increased in case of a semiconductor the free electron gets more energy to cross the energy gap to the conduction band from the valence band.so now more electrons can go easily to ...
166 views

### Output in a half wave rectifier

In a half wave rectifier only a single diode is present. One end of the secondary wire of the transformer is connected to the p side of diode while the other to the load resistor. The n side is ...
47 views

### Point resistance

The resistance of a given object is expressed through: $$R=\rho\frac{l}{A}$$ I'm wondering if there is any quantity like resistance at a specific point. For example, $R$ for a copper wire with l=...
470 views

### PN Diode connected in parallel with resistor

I just want to know that my logic is sound for the above question. So, since the diode is connected to a resistor in parallel, for the voltage values where V is less than the breakdown voltage, the ...
50 views

### I-V curve of Zinc oxide film deposited on glass

Good day! I'm looking for any suggestion about my research. So basically my research is about electrical properties of ZnO film deposited on glass via spray pyrolysis. I want to determine the ...
61 views

### Wiedemann–Franz law for Copper at 100 °C

I have a colossal temperature (T)-dependent expression which has both the thermal conductivity (κ) and the electrical conductivity (σ) of copper. T fluctuates around 100$\pm$10 °C. For ...
138 views

### Can a Schottky diode rectify thermal noise from a resistor working at the same temperature? [closed]

I have proof that an all-hot thermionic diode can do it (see my article "Diode Rectifies Thermal Noise" in Research Gate), but no proof in this case. (Please do not rely on the Second Law of ...
1k views

### Are thermistors and filament bulbs ohmic?

Conductors are ohmic if they have a constant resistance given that the physical conditions, such as temperature, are constant. A filament bulb and thermistor are considered to be non-ohmic because ...
50 views

### Need help on the electrical resistances of semiconductors and metals and their dependance on temperature

So I was doing some problems and this came up : - Two resistors $A$ and $B$ having resistances $R_1$ and $R_2$ respectively at $0^{\circ}C$ and temperature coefficients $α_1$ and $α_2$ are joined ...
438 views

### Diode IV experiment

Ive been looking at experiments to look at the IV relationship for a LED, but I see most of them use a rheostat instead of a series variable resistor and my question is, what is the advantage of using ...
46 views

### Resistance and Voltage [closed]

I understand that superconductors have zero resistance, but with zero resistance there should be no voltage right? because V=IR Also, why do diodes have such high resistance but no voltage in the ...
972 views

### Specific resistance of semiconductors

Why does the specific resistance of a semiconductor decrease with an increase in temperature, as an increase in temperature should cause the specific resistance to increase?
1k views

### Intrinsic semiconductor having less conductivity than extrinsic conductor

The question is quite simple.Why intrinsic semiconductor has less conductivity than extrinsic semiconductor? I want to know the exact doping concentration per atoms in extrinsic semiconductor relative ...
40 views

### How can I create an ohmic contact with selenium?

I would like to be able to measure the electrical resistance of selenium past its melting point, but to do this I need to create an Ohmic contact between the selenium and my multi-meter. What metals ...
51 views

### Regarding reservoir capacitor in diode bridge [duplicate]

In my recent physics lab I constructed and examined the diode bridge (see https://en.wikipedia.org/wiki/Diode_bridge#Output_smoothing). In particular I was interested in the smoothing properties of ...
338 views

### Why does this circuit provide the data needed to plot an I-V graph?

So this circuit is used to collect data to plot an I-V curve of a semiconductor diode. Is the variable resistor on that side of the circuit as to not effect the voltage? If someone could give me a ...
30 views

### How am I obtaining silicon with resistivity proportional to the number of conduction electrons?

The resistivity of silicon is given by $$\large\rho=\rho_0e^{\Large{{\frac{E_g}{2k_BT}}}}$$ and the number of conduction electrons in a semiconductor conduction band is \large n_{\text{...
214 views

### Photodiode circuit

I'm stuck at the following question: At peak intensity, the photo-diode outputs a current of $I=34\;\mathrm{\mu A}$. At that point $u_0$ needs to be $5\,\mathrm V$. Pick a value for $R$ that ...
479 views

### Why does the resistance of a PN junction reduce with increasing voltage?

In a small signal model we define a transient resistance. This resistance denotes the amount of change of current per differential change in voltage. One can easily notice from a standard $I-V$ ...
74 views

4k views

### Resistance & temperature of semiconductor

From what I have read about semiconductors, the reason their IV characteristic shows a decrease in resistance is because as voltage is increased, current is increased. However, the reason for the ...
4k views

### why activation energy of semiconductor changes as temperature changes

why activation energy of semiconductor thin films changes as temperature changes. I know that this is due to different conduction mechanisms. Intrinsic conduction mechanism which occurs at high ...
162 views

### Resistance of depletion region

The ideal diode equation is : I=Io[exp(qv/kT)-1]. My question is when we want to represent this ideal diode, it will be represented by a resistance of depletion region right? but is this resistance ...
482 views

### Internal resistor in a diode

When we talk about the resistance of a diode (of the P and N region), is this resistance like the one inside an Electro-Motive Force or it acts like a normal resistor (external electric field exist)? ...
533 views

### Diffusion current and resistance of a diode

In a diode, there is a resistance in the p and n region, and electric field is required to move the charges in forward bias conditions. My question is: when there is diffusion current is the electric ...