Improve solar cell technology for a cleaner future.
Next to Si-based solar cells, devices based on chalcogenide thin films, such as CdTe and Cu(In,Ga)(Se,S)2 (CIGS), are at the forefront in thin film solar cell technology. CdTe solar cells are now the largest thin-film technology in production with typical commercial module and record cell efficiencies of 10% and 16.7%, respectively. In the meantime, CIGS technology, as the main thin-film competitor, has reached module and cell efficiencies of 9%–12% and above 20%, respectively. However, reliance on the heavy metal Cd and on the non abundant elements In and Te presents a major barrier towards meeting the multi-terawatt-scale target for renewable energy supplied by photovoltaics. Moreover, thin film PV has to compete with present efficiencies of silicon solar cells above 20%. Therefore, multi-junction PV solutions will be needed in the future. Kesterite materials such as Cu2ZnSn(S,Se)4 or Cu2ZnGe(S,Se)4 are emerging alternative chalcogenide solar cell absorbers that provide diversification away from the non-earth-abundant elements mentioned above.
This master thesis topic consists of the fabrication of Kesterite materials on glass substrates using a two step process. This process involves first the deposition of metal layers, followed by the selenization proces in H2Se gas. Physical and optoelectronic characterization of the fabricated layers will be performed before the layers will be turned into solar cells. Electrical measurements to be performed on the solar cells consist of current-voltage and capacitance-voltage measurements of Kesterite solar cell structures. All measurements will be performed as a function of temperature and illumination intensity, in order to fully characterize the diode parameters of the solar cell structure and to gain insight into the dominant recombination processes in the cell. Optical measurements to be performed consist of temperature and intensity dependent photoluminescence and time-resolved photoluminescence measurements. These measurements will allow further insight into the different recombination mechanisms in the solar cells.
The different characterizations will be linked to the growth of the absorber in order to optimize the absorber quality for solar cell applications.
Required degree: Master of Engineering Technology, Master of Science, Master of Engineering Science
Required background: Energy, Materials Engineering, Physics
Type of project: Internship, Thesis, Combination of internship and thesis
Duration: 6 months minimum duration
Imec allowance will be provided for students studying at a non-Belgian university.