In the figure below the absorption coefficient as a function of the wavelength for several semiconductor materials is presented. Let's consider monochromatic light of photons with energy of Eph=1.55eV that incidents a film with thickness d. If we ignore possible reflection losses at the rear and front interfaces of the film, what thickness d (in μm) is required to achieve a light absorption of 90%?
UPDATE: Since it was very difficult to accurately read off the absorption coefficient values from the graph above, we have chosen to provide you with these values. The absorption coefficients for the different semiconductor materials at α(800nm) are:
(a) Cadmium telluride (CdTe) is a semiconductor witha band gap, Eg, of 1.45 eV. Calculate the value of the absorption edge of this material. Express your answer in meters. (b) Shown below are several % absorption vs. wavelength
Calculate how thick an absorber needs to be to absorb 25% of the incoming light using the Lambert-Beer law for absorption. How is the small gain coefficient k of a laser defined in relation to the absorption coefficient ƒÑƒ¯
Why is it important to determine the wavelength of maximum absorption? I assume we are talking spectroscopy here? When describing the spectrum it is usual to record the wavelength of a maximum absorption (there may be several
On the graph light absorption in % vs wavelength, how come the color of chlorophyll is green? Since this is an absorption spectra, isn't it supposed to absorb blue and red and not green? Rather, it reflects green??? How would the
In the context of a silicon-based semiconductor, match each of the following descriptions to the type of semiconductor: n-type or p-type semiconductor. a) contains electron holes; b) dopant-phosphorous; c) contains extra