Fundamentals of Photovoltaics

Students present projects on photovoltaic lights for Lighting Africa, nextgen modules, and nextgen simulation.

Students present projects on smart retrofitting and photovoltaics grids.

This lecture continues with wafer fabrication by ribbon growth, then cell and module manufacturing, next-generation silicon technologies, and materials availability.

This lecture is about methods to characterize solar cell performance and properties, specifically techniques to measure short circuit current losses, open circuit voltage, and fill factor.

After a brief in-class activity with silicon and multijunction PV devices, the lecture reviews trends in global and U.S. investments in renewable energy and overall R&D, and ends by considering how one might evaluate a new PV technology.

This lecture covers many practical aspects of PV manufacturing, testing, system design and real-world deployment.

This lecture introduces some economic and policy factors that affect PV deployment.

This lecture covers material properties affecting performance, including minority carrier diffusion length, minority carrier lifetime and mobility, recombination, carrier concentrations, and mobility-limiting mechanisms.

This lecture features a detailed look at German policy initiatives for renewable energy, a survey of state-run programs in the U.S., and discussion of the 2011 PV module market oversupply with sustained falling prices and industry consolidation.

This lecture begins with the question, "why silicon?," followed by an overview of current manufacturing methods and market shares, feedstock refining, and wafer fabrication.

This lecture continues discussion of thin film technologies, looking at amorphous silicon and copper indium gallium diselenide (CIGS), and some closing thoughts on materials availability.

This lecture examines the practical realization and theoretical limits of solar cell efficiency, with a closer look at solar simulators, making measurements, and material and device-based sources of efficiency loss.

This lecture concludes the unit on PV technologies. Topics include temperature, shading and mismatch effects on field performance; intermediate band materials; hot carrier cells; and bulk thin films.

This lecture begins with the purpose of contacts, common types, and the impact of good and poor contact on IV characteristics. Compares Schottky and Ohmic contacts, the role of surface states, and ends with a brief look at heterojunctions.

This lecture introduces thin film solar technologies: generic advantages and disadvantages, device structures and performance, fabrication by vapor deposition, and market issues. The lecture ends with with a look at cadmium telluride (CdTe).

This lecture on advanced semiconductor physics introduces quantum efficiency, and explores why real PV cells deviate from an ideal diode model. Also: series resistance for a solar cell; Fermi energy as a function of dopant, illumination and temperature.

This lecture describes the efficiency of a solar device, from input to output. Topics include: Snell's law, how light interacts with matter, and key methods used to improve optical absorption, including texturization and anti-reflection coating.

This lecture is about semiconductor pn-junctions: how they are formed with doping; how current flows in them, differentiating between drift and diffusion currents; and voltage and bias across pn-junctions, with reference to band diagrams and IV curves.

This lecture describes how semiconductors respond to optical charge excitation, and looks closely at the role of the band gap in determining maximum efficiency.

After a brief overview of course structure and objectives, this lecture introduces solar energy as a good match for world energy demand. A history of photovoltaics, survey of key technologies, and photovoltaic device fundamentals complete the session.

This lecture explores factors that affect the amount of sunlight reaching Earth's surface: e.g. orbit and tilt, scattering in the atmosphere, weather, and diffuse vs. direct sunlight.

This lecture begins with the current-voltage (IV) response of a pn-junction, under varied illumination & bias conditions. IV curves lead to solar conversion efficiency, a key performance metric that sets the PV device area needed for a given power output.

This video summarizes how a solar cell turns light-generated mobile charges into electricity, highlighting the cell's physical structure with layers with different dopants, and the roles of electric fields and diffusion of holes and electrons.

This video shows how solar cell efficiency is improved by wet etching the silicon wafer surface into microscopic "pyramids," so that more incident light is trapped within in the cell rather than reflected back into the air.

Pure silicon has very low conductivity. This tutorial explains how "doping," the addition of very small amounts of elements like P and B to the Si material, create mobile charges that dramatically boost the material's conductivity.

This video describes how light shining on a Si semiconductor causes its conductivity to rise, by photon energy breaking covalent bonds, creating mobile electrons and holes.