Solar Cells

1. Solar spectrum and photon flux; black-body radiation and solar irradiance;
2. Semiconductor physics: energy band diagram, doping, thermal excitation, minority and majority carriers;
3. Semiconductor’s absorption coefficient and optical excitation, charge carrier generation, excitons, charge carrier lifetime, electron-hole recombination mechanisms, charge carrier transport mechanisms;
4. Principles of photovoltaic energy conversion discussed with the case study of crystalline silicon solar cell, p-n junction under equilibrium and dark condition, under the application of an external bias, under sun-light illumination.
5. Quantitative model of the currents involved in a p-n junction and derivation of the JV diode equation, quantitative model of the p-n junction under illumination and derivation of the JV characteristics;
6. Solar cell characterization: JV characteristics, ideality factor, shunt and series resistances; EQE, sun simulator, photo-luminescence, impedance spectroscopy;
7. The Shockley-Queisser thermodynamic limit to sunlight-electricity conversion;
8. Crystalline silicon (c-Si) photovoltaics: device architecture (homojunction, heterojunction, surface passivation concepts, optical management concept, contacts), evolution of the c-Si solar cell efficiency and key industrial c-Si PV technologies (PERC, TOPCon, HJT);
9. Key thin film deposition technologies (of relevance for PV device architecture) and film opto-chemical-electrical characterization;
10. Basic concepts and working principles of thin film inorganic solar cells (amorphous/micro-crystalline silicon, CdTe, CIGS) and organic solar cells, with the opportunity to deepen these technologies through group assignments. Other technologies (such as GaAs, nanowires and quantum dots) will be addressed via group assignments.
11. Basic concepts, working principles and state-of-the art of metal halide perovskite solar cells;
12. Multi-junction solar cells, 3rd generation solar cells and advanced optical management;
13. Overview of other, relevant topics towards further deployment of photovoltaics: status PV in the overall electricity demand; sustainability/recycling aspects; upscaling; other challenges (e.g., stability).

After the end of this course, the student will be able to:

1. Explain the fundamental physical properties of charge carriers in semiconductors, including concentration, scattering time, carrier lifetime, and diffusion length, and describe the behaviour of semiconductor junctions under dark conditions, applied bias, and illumination.
2. Apply mathematical models to derive and analyze the current–voltage characteristics of a diode under both applied voltage and solar illumination.
3. Describe the physical and operational principles of major photovoltaic technologies, as discussed in classes and addressed through group assignments.
4. Evaluate and critically compare different photovoltaic technologies in terms of material properties, device architectures, fabrication approaches, and current technological maturity.
5. Simulate carrier concentration profiles and electric field at a p-n junction and adopt photovoltaic simulation software to model and interpret the optical and electrical behaviour of solar cells.
6. Collaborate effectively in a group project to analyze and present the state of the art, key challenges, and future prospects of a selected photovoltaic technology.

Recommended: Classical thermodynamics (as taught in Thermodynamics- 32TDY); Basic concepts of quantum (as taught in Introduction to quantum physics- 32IQP) and material science (as taught in Nanomaterials- 34NPC); basic knowledge in mathematics (as taught in in Calculus).

• Other resources (ebooks available at the TU/e library) provided during the course
• “Principles of solar cells, LEDs and diodes: the role of the p-n junction”, A. Kitai - as e-book in the TU/e digital library
• Slide handouts - CANVAS
• Matlab 2013 / 2014 a en 2014b via TU/e site http://www.mathworks.nl/support/sysreq/roadmap.html (Mathworks)
• Scientific articles
• “Physics of Semiconductor Devices”, S.M. Sze