Design and construction of Optical Systems (in particular Michelson Interferometers and spectrometers)
The Michelson interferometer is a key optical instrument to measure very small changes in the refractive index or thickness of materials. Similarly, a Fourier Transform Infrared Spectrometer is an instrument used in chemical analysis almost in daily-based. In this project, we will design and assemble a Michelson Interferometer using HeNe laser and optical components such as mirrors and lenses. Later in the project, we will switch the light source to a white light. Using LabVIEW programming and a motor to move one of the mirrors, we will construct a tens-of-thousands dollar worth equipment – a Fourier Transform Infrared Spectrometer. Image (left) is from S. Yerci, M.S. thesis.
Characterization of solar cells
A solar cell is a device that converts the energy of light directly into electricity. Countries such as Germany, Japan, Spain and USA have been installed large amount of solar power plants as local, renewable and clean energy supply. Turkey is expected to join the club, soon. In this project, we will examine the performance of various types of solar cells fabricated at METU. Image (left) is retrieved from http://www.electronics-lab.com/blog/?p=14624 on March 04, 2014.
Calculation of maximum efficiency of practical tandem solar cells
The maximum theoretical efficiency – Shockley - Queisser limit or detailed balance limit – of a solar cell using a p-n junction was first proposed by Shockley and Queisser in 1961. According to the Shockley - Queisser limit a semiconductor with a band gap of 1.34 eV can reach a maximum efficiency of 33.7%, while silicon with its band gap of 1.1eV can reach a maximum efficiency of 29%. However, solar cells fabricated from semiconductors with different band gaps (i.e. tandem solar cells) can surpass this limit. In this project, we will calculate the maximum achievable efficiency for tandem solar cells fabricated from semiconductors with two different band gaps using practical parameters (i.e. short-circuit current, open-circuit voltage, fill-factor and absorptance) obtained from recent publications. Using LabVIEW programming, we will create a simulation platform where users can easily make combinations of various materials to form tandem solar cells and see the resulting theoretical efficiency.