Recent content by snoothie

thanks for correcting. So you are saying a nn junction = schottky diode, and the band bending should be like what we see for a schottky contact? except that the metal junction is now replaced with another n type semiconductor junction?

oh sorry. My bad... I was referring it as: Eph = (hc/e) x wavelength e = 1.6 x 10^-19 eV Thank you very much for your help.

Ok. thanks for the leads. we can use: E = hc/e.wavelength then, the flux is simply: Eph x photons/s, which also is the optical output power in watts?

Homework Statement A blue semicon LED is connected in series with a 10ohm series resistor to a voltage source. The LED emits 4.03 x 10^16 photons/s at a wavelength of 400nm. The current flowing through the LED is 40mA and the voltage across the LED is 3.5V. Calculate the power conversion...

think there will be a slight band bending due to a efield between the nn junctions which is due to the difference in donor concentrations? (gradient of 10^16 - 10^15 / x0 - x1)? then due to the field there should be some drifting of electrons from the n junction with higher nd concentration to...

Hi, If we had two junctions one side with Nd=1016 & another side with Nd=1015 put together. What happens in such a junction? Would we see electron diffusion from the high donor concentration side to the lower concentration side? What should the band diagram of the junction look like...

oh silly me... I was only thinking about addition and subtraction and did not think about shifting T over to the left side and shifting all the terms from left side to the right side of the equation as the denominator of -12997. I kept thinking goodness how to work this with...

Yup got it. Thanks. Seems like there isn't any easier ways. no? Did take log on both sides to try making the equation easier to work with, but since trial and error is the way to solve this problem. I found it easier to just plug in no.s into \frac{10^{24}}{2.912*10^{38}} =...

Homework Statement trying to work out the answer for the temperature T from the equation... (1012)2=(2.8*1019)(1.04*1019)(T/300)3exp(-1.12/KT) Homework Equations the equation was derived from ni2=NcNv(T/300)3exp(-Eg/KT) The Attempt at a Solution Only simplified the equation to...

solved. but must take note to make the equation: [n0-(1.5*1015)]2=(1.5*1015)2+0.0025n02 Thanks and cheers

Homework Statement Can someone advice me how to solve this square root equation? n_{0}=1.5*10^{15}+\sqrt{(1.5*10^{15})^{2}+[(0.05)n_{0}]^{2}} The answer should be n0=3.0075*1015 I can't figure out how to open up the square root to solve the equation for n0. Stuck here staring at the...

Hi Marcus, Thanks for your great help. Glad that I'm on track now. Been slugging out this question for days... one thought, is it correct to say that when diodes are connected in series, we are pushing back the threshold voltage by 3 times (from 0.7v to 2.1v) in my case but when we find...

Thanks. looks like the graph posted in the 1st thread is now obsolete. Am i right to say that the equation can also be used in a Dc only circuit? Still quite confused on this part, as i found this equation from an example with Ac supply added to Dc supply. So not quite sure if this equation...

Hi es1, Thanks for your advice. Been searching for an answer to this for few days. Will using the small signal ac resistance formula (Rd = nVT / Id) be more appropriate and accurate way of finding Rd? If so is it applicable to a circuit that only has Dc voltage supply and no ac input? Can...

can someone advice me on how the graph should look like for a circuit with diodes connected in series? Can we model the diodes this way? Attached picture shows the graphed charecteristic for 1 diode. If its for 3 diodes, how should the graph look like? Am i right to say that Vt will...