OPTOELECTRONIC AND PHOTOVOLTAIC DEVICES

Second cycle degree in ELECTRONIC ENGINEERING

Campus: PADOVA

Language: English

Teaching period: First Semester

Lecturer: ENRICO ZANONI

Number of ECTS credits allocated: 9


Syllabus
Prerequisites: Basic knowledge concerning laws of electromagnetism, optics, atomic physics. Basic knowledge concerning working principles of semiconductor devices
Examination methods: Mid-term and final tests during the course, including numerical problems and simple questions concerning operation of optoelectronic and electronic devices. After the end of the course, written tests with numerical problems and questions.
Course unit contents: Elementary quantum mechanics. Heterostructures. Anderson theory for band alignment. Band diagrams. Capacitance-voltage profiling. Quantum wells. Compound semiconductor devices, heterojunctions and their properties. Heterostructure Field Effect Transistors and their applications. Modulation doping and High Electron Mobility Transistors (HEMTs); applications to 5G telecommunication infrastructure and to power electronics. Optical properties of semiconductors. Radiative transitions, light absorption; rate equations. Non-radiative recombination, Auger recombination. Theory of radiative recombination in semiconductors. Light-emittin devices, Light Emitting Diodes (LED). Current-voltage LED characteristics. Non-ideality of I-V characteristics, parasitic resistances. Carrier loss and carrier overflow; electron blocking layers: case histories, efficiency droop. Dependence on temperature of electrical and optical characteristics. Internal and external quantum efficiency, extraction efficiency. High efficiency LEDs. Semiconductor lasers: conditions for laser oscillation, gain threshold voltage.
Mode propagation in the optical cavity. Laser diodes operating principles. Steady-state rate equations. Optical power vs current laser characteristics. Semiconductor lasers for optical fiber communications. Superluminescent diodes. Photodetectors: pin diodes, avalanche photodetectors (APD), Metal Semiconductor Metal detectors (MSM), fototransistors. Solar cells: structure, operating principles, deviations from ideality. Optimized structures for solar cells: multijunction cells, thin film photovoltaic devices. Solar concentration. Reliability in optoelectronics, assignment of master thesis topics.