A thin film is a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many applications. A familiar example is the household mirror, which typically has a thin metal coating on the back of a sheet of glass to form a reflective interface. The process of silvering was once commonly used to produce mirrors, while more recently the metal layer is deposited using techniques such as sputtering. Advances in thin film deposition techniques during the 20th century have enabled a wide range of technological breakthroughs in areas such as magnetic recording media, electronic semiconductor devices, Integrated passive devices, LEDs, optical coatings (such as antireflective coatings), hard coatings on cutting tools, and for both energy generation (e.g. thin-film solar cells) and storage (thin-film batteries). It is also being applied to pharmaceuticals, via thin-film drug delivery. A stack of thin films is called a multilayer.
In addition to their applied interest, thin films play an important role in the development and study of materials with new and unique properties. Examples include multiferroic materials, and superlattices that allow the study of quantum phenomena.
Homework Statement
[PLAIN]http://img403.imageshack.us/img403/2696/33095583.jpg
The attempt at a solution
I simply took 425 nm and divided it by 4 by using the destructive reflection from thin film. I got 106 nm as my answer, which is c. Is this correct?
Homework Statement
(1 / 2) (λ1 /nfilm) (m1) = (1 /4) (λ2 / nfilm) (2m2 +1)
(2*m2 + 1) / (2*m1) =λ1 / λ2 = 640 nm / 512 nm = 1.25
We want to solve for m1 and m2.
I have realized that using m1=m2=2 works but I can't figure out how to reach this conclusion mathematically.
Please, any...
Hello there,
I'm an undergrad in my 3rd year and I'm doing an investigation into the 'Preparation of Thin Films and their use in Hall Effect measurements.'
We are making thin films of bismuth on glass (with pre drilled terminals) in a vacuum system.
The way they suggest measuring the...
Homework Statement
Hi all, i have a question on thin film interference.
Lets say there is an oil drop on the surface of water. Light reflected from the oil drop is observed from above. Explain why interference fringes are not seen when the thickness of the oil drop increases...
Hi! I have samples of multiple thin films. Thin film of which refractive index needs to be estimated is sandwiched between substrate and capping layer of known refractive indices and extinction co-efficients. I have transmission and reflection spectra of the samples and with the help of these...
Interference with thin film :(
Homework Statement
A soap film in air is 320nm. thick. If it is illuminated with white light at normal incidence, what colour will it appear to be in reflected light (assume that the index of the soap film is 1.33).
Homework Equations
The condition for...
Homework Statement
I'm just trying to figure out what all the variables are in an equation I'm using for thin film reflectivity. Any advice beyond that would be appreciated though...Homework Equations
rthin slab=(-i * \lambda * \rho * r0 * \Delta)/(sin(\alpha))
note: alpha here isn't an...
Problem
A thin film of oil (n = 1.30) is located on a smooth, wet pavement. When viewed perpendicular to the pavement, the film reflects most strongly red light at 640 nm and reflects no light at 548 nm. How thick is the oil film?
Equations and Attempt
Refractive index:
air - 1
oil -...
Homework Statement
A glass (Refractive index 1.33) is coated with a thin film. (Refractive index 1.50)
Find the minimum thickness of the film, if the glass is to transmit light of wavelength λ.
Homework Equations
The Attempt at a Solution
Light reflected from the upper surface of...
Hi, I'm a high school physics student and I'm having a lot of trouble with thin film interference
Homework Statement
A thin layer of oil (noil=1.25) is floating on water (n=1.33). How thick is the oil in the region that strongly reflects green light (λ=556nm)?
Homework Equations
noil/nwater...
I need to write up some stuff with general information about different interfaces used in Thin Film Processing.
I'm pretty sure its a way to analyze the quality of the different procedures.
* Abrupt Interface
* Mechanical Interface
* Graded Interface
* Compound Interface
* Psuedo...
Homework Statement
A thin film with a refractive index of n=1.50 is surrounded by air. Wavelengths of light 360, 450, and 602 nm are the only visible wavelengths missing from the reflected light. What is the thickness of the film.
Homework Equations
The Attempt at a Solution
One...
Hello!
There're very thin (4-15 nm) semiconductor films (passive film) formed on stainless steel by electrochemical method. In a electrochemical cell, I applied potential on stainless steel electrode to adjust Fermi level of the semiconductor passive film. I think that band bending take place...
For instance, I know if a light wave traveling air (n = 1) enters a thin film of water (n = 1.33), there will be a phase difference.
My textbook sol'n manual states that there will be a 180 degree phase difference for a wave of light that reflects of the top of the air-water boundary, but NO...
This is not a homework problem but a general problem I've been having when studying for physics.
What is the formula for "thickness" for thin film interference problems?
I read somewhere that there are a variety of equations that can be used--depending on interferences, and etc--however, I...
Hi guys
I wanted to know if somebody can guide me on how to run a symmetrical grazing angle XRD on carbon thin films. I have been doing asymmetric grazing angle which predominantely measures diffraction pattern which is out of plane (normal) to the substrate. Now, I want to do an in-plane...
Homework Statement
Light of wavelength \lambda = 500nm, produced by an extended source, is incident at an angle of \phi= 30 degrees from the normal upon a dielectric film of refractive index, n=2, supported on a solid planar substrate. Reflectivity minima are observed to have an angular...
I've learned that when a wave is partially transmitted and partially reflected, it loses some of it's amplitude in order to conserve energy. How then, in thin film interference, can one wave produce complete destructive interference with the other if it has been partially transmitted? Wouldn't...
Homework Statement
What is the thinnest film of a coating with n = 1.43 on glass (n=1.52) for which destructive interference of the red component (660 nm) of an incident white light beam in air can take place by reflection?
Homework Equations
2t = m*lambda?
The Attempt at a...
1. The problem statement:
A wavelength (λ)550 nm light ray traveling thru a viscous medium n1= 1.46 strikes a a crystal n3=1.5 protected by a film n2=1.25.
[b]2. Relevant equation:
How can I determine the min thickness of the antireflective coating used to minimize the reflection of...
Friends,seeking some doctoral Researchers in the sub-domain of thin-films,I would want
the following assistance from any of them: (1)A Standard Reference Book that addresses
introductory (Post Grad.) and advanced (PhD) topics in thin Films.(2) Some standard Lab
projects that has been...
Homework Statement
Question:
A soap bubble of index of refraction 1.48 strongly reflects both the red and the green
components of white light. What film thickness allows this to happen? (In air, the wavelength of red light is 716 nm, of green light 511.429 nm.)
n = 1.48
\lambda(r) =...
In deposition of thin film on a p-type silicon, how to make sure the thickness of the thin film will not affect or affect the least the electrical(Hall Effect) and structural properties? how to know how thick is the thin film that most suitable? can it be calculated? by the way, the thin film...
Not really a homework problem. Just wanted to know:
When light moves from a medium of lower index of refraction to that of a higher index of refraction, the reflected ray suffers a phase change. (Thin film interference)
But the other way round, this doesn't happen. This can be shown by...
Homework Statement
A uniform film of oil (n=1.31) is floating on water. When sunlight in air is incident normally on the film, an observer finds that the reflected light has a maximum at wavelength (lambda) = 450nm and a minimum at wavelength (lambda) = 600nm. What is the thickness of the...
Homework Statement
The thin film is of two glass with air in the middle.
refractive index of...
air: n=1.0003
glass: n=1.5
lamba=632.8nm
Q1.) Calculate optimum thickness of the film (for 1st order interference)
Q2.) Why does the distance between interference fringe beome longer...
While completing my problem set for this chapter, I came across 5 problems I could not solve. I thought it might be rather annoying if I posted six posts, so I'm putting all my work and such here. I don't expect one person to try to help me with all of them, just one or two at a time will do...
Homework Statement
A transparent oil with an index of refraction of 1.25 spills on the surface of the water (n=1.33), producing a maximum of reflection with incident orange light (\lambda = 602nm in air.) Determine the lowest possible thickness (in nm) of the oil slick.Homework Equations...
I don't have a particular homework inquiry to ask, just some questions I have about thin-film interference and its related equations. I was told by my instructor to learn these concepts on my own and I am just having a few problems I want to clarify.
1) Equations related to thin-film...
Hello,
I'm currently doing a project which involves generating power from thin film solar panels, I have found the kind I need on a site (http://www.siliconsolar.com/flexible-solar-panels-6v-p-16205.html) which suits my size and power criteria but I am not totally sure how I would go about...
Hi everyone!
Here's the problem related to thin film interference. I mean, it's not quite a problem. I've been looking for the formulae related to this type of interference and fount two different things in two different textbooks.
It's the formula for the optical difference of the wave...
I am trying to model intrinsic stress of some thin film heterostructures. As I am not a modeler but an experimentalist/processor by trade, I would prefer to minimize the amount of time I spend banging my head against the wall trying to find out if this software is appropriate. So, my question...
Homework Statement
A thin film of MgF2 with n = 1.38 coats a piece of glass. Constructive interference is observed for the reflection of light with wavelengths of 500 nm and 625 nm.
Part A -
What is the thinnest film for which this can occur?
Homework Equations
t = lambda/2n *(m + .5)...
Homework Statement
An oil film (index of refraction no = 1.48) floating on water (index of refraction nw = 1.33) is illuminated from above by white light at normal incidence. The film is 360.0 nm thick.
What is the longest visible wavelength that will be strongly reflected?
What is...
Homework Statement
What is the minimum (non-zero) thickness of a benzene (n = 1.501) thin film that will result in constructive interference when viewed at normal incidence and illuminated with orange light (lamba = 615 nm)? A glass slide (ng = 1.620) supports the thin film
answer= 204 nm...
My question concerns thin films of varying thickness. I have a basic understanding of thin film interference, and understand the effects of thickness on wavelength, and that with increasing thickness color fringes will be evident. I understand that the color fringes come from:
n*t = m*\lambda...
A camera lens (n = 1.80) is coated with a thin film of magnesium fluoride (n = 1.45) of thickness 80.0 nm. What wavelength in the visible spectrum is most strongly transmitted through the film?
I have tried to solve this problem for quite a while now, and i hate to admit that there might be a...
Homework Statement
A pair of slits separated by d = 1.30 mm is illuminated with light of l = 610 nm wavelength and falls on a screen L = 2.00 m away. A piece of glass with index of refraction n = 2.2 is placed at one slit. If the maxima shift is Dx/2, and falls on a minimum, what was the...
Homework Statement
A mixture of red light (wavelength vacuum = 652 nm) and green light (wavelength vacuum = 477 nm) shines perpendicularly on a soap film (n = 1.333) that has air on either side. What is the minimum nonzero thickness of the film, so that destructive interference removes the...
hi there
im searching for an answer about matter magnetism.
actualy, i need to know which energies of anisotropy are so different betwen the bulk and a thin-film .
then i need to know which energy of anisotropy is so different between a nanowire and a thin-film.
10x for your repply
Hey guys, I was wondering if someone could explain to me when Thin Film Interference will produce constructive/destructive interference. I think I might understand it, but I'm not 100% sure and I have a test coming up soon. Any help would be great!
Ok, so I know we have the equation:
2t =...
A thin film is put on the surface of glass, with indexes of refraction of x and y respectively.
If light, with wavelength L in air, is reflected from the 2 sides of the film, to interfere constructively, what is the minimum thickness required.
The question is stated just like that, so I...
I was having a bit of trouble with this question:
A thin oil slick of refractive index 1.3 floats on water. When a beam of white light strikes this thin film vertically, the only colours enhanced in the reflected beam seen in air are orange-red (650nm) and violet (430nm). What is the thickness...
I need help with this question:
"Name the wave phenomenon that is responsible for the formation of regions of different color when white light is reflected from a thin film floating on water."
In my handy-dandy high-school physics book, it says that "The different thickness of the gasoline...
Consider a soap film where both sides of the film is air.
So reflected light has a π phase change.
Consider constructive interference,
2 d "nfilm" + 1/2λ = nλ , where "nfilm" is the refractive index of the film and d is the thickness the film.
Due to the gravity, the film at the bottom...
Homework Statement
A thin film of oil (n = 1.23) is located on a smooth, wet pavement. When viewed perpendicular to the pavement, the film reflects most strongly red light at 640 nm and reflects no light at 569 nm. How thick is the oil film?
Homework Equations...
Homework Statement
One of the beams of an interferometer passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill thr container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610...