Lecture Notes

Unit 1: fundamentals of PV devices, systems


Overview of world energy, climate challenges. Solar resource availability, insolation, atmospheric absorption, direct and diffuse radiation, angular dependence, seasonal variability. Options for harnessing solar energy (thermal, catalysis, combined technologies, photovoltaic), and their respective current and projected costs/potential, compared to traditional sources. Centralized vs. decentralized power. Dispatchable vs. non-dispatchable power.

Solar resource (PDF - 2.5 MB), (PDF - 1.6 MB)

Charge excitation and conduction

How light is converted to electricity. Direct and indirect semiconductor bandgaps. Optical properties of semiconductors. Introduction to intrinsic, doped semiconductors, conjugated polymers. Minority carrier mobility, lifetime, diffusion length. Charge excitation in non-semiconducting materials. Conduction, dispersive hopping.

Light absorption, charge excitation, and transport (PDF - 1.7 MB), (PDF - 1.7 MB)

Charge separation

How voltage, current are formed. Minority-carrier devices: semiconductor pn-junctions. IV curves. Majority-carrier devices (organics). Quantum-size effects of charge separation.

Charge separation: how current and voltage are formed (PDF), (PDF)

Charge collection, and the solar cell device

Metallization. Solar cell device architectures. Common limitations of efficiency, short-circuit current, fill factor, open-circuit voltage.

Charge collection (PDF - 1.2 MB)
Quiz #1 review: fundamentals (PDF)
Unit 2: commercial and pre-commercial PV technologies

Commercial technologies, part 1: crystalline silicon solar cells

Feedstock: silicon refining, Siemens, fluidized bed reactor, metallurgical route, novel concepts.

Crystal growth: ingot silicon, ribbon and sheet silicon. Wafering.

Cell fabrication: methods, architectures, concepts. History, state-of-the-art. Emerging trends, cutting-edge technology. Role of innovation.

Wafer silicon-based PV (PDF - 2.4 MB), (PDF)

Commercial technologies, part 2

Thin Films: thin film silicon (incl. amorphous, SiGe, micromorph, tandem cells), cadmium telluride, copper indium gallium diselenide. Precursors. Deposition processes and technologies.

Other technologies: concentrator devices and materials, heterojunction devices, photovoltaic thermal.

Thin films: materials choice and manufacturing (PDF - 1.2 MB)
Review: crystalline silicon and thin film PV technologies (PDF - 1.6 MB)

Developing technologies

Organic PV. Organic/Inorganic hybrid systems (dye-sensitized, nano hybrid). Inorganic nanostructured materials, incl. quantum dots, nanostructured devices, and layered structures. Biological and biomimetic systems. Novel thin film materials, multiband semiconductors, hot carrier devices, spectrum splitting.

Guest Lecture, Mark Baldo - Trends in organic solar cells
Emerging PV technologies (PDF 1.2 MB)
Unit 3: cross-cutting themes in PV

Photoelectric conversion efficiency

Theoretical efficiency limits. Efficiency loss mechanisms. Optical losses, recombination losses, surface recombination velocity, series and parallel resistance (shunts). Specific loss mechanisms in each technology class. Evaluation of loss mechanisms, common characterization tools.

Efficiency limits and loss mechanisms (PDF - 1.2 MB), (PDF)

Modules, systems, and reliability

Module manufacturing: encapsulation materials, availability, trends.

Systems: grid-tied and stand-alone, tracking and non-tracking. System components, including balance of systems components. Design criteria, tradeoffs, costs. Building integration, BIPV. System integration. Scaling, and integration into the power grid. Appropriate technology selection. Life cycle analysis. The energy storage challenge.

Failure: failure modes in stationary and tracking systems, accelerated testing, field testing, service and warranty contracts.

Modules, systems, and reliability (PDF)

Cost and manufacturability

Cost: building a cost model, key drivers of cost, substitution economics.

Manufacturing: environments, models, operations, process yield, handling. Predicting shortages and bottlenecks.

Scaling: the multi-GW plant. Production technologies.

Background in remaining topics (PDF - 1.2 MB)
Guest Lecture, Mike Rogol - Prices, markets, trends

Price, markets, and subsidies

Price and markets: what sets price (and profit), energy future and overview of renewable energy sources, economics and market dynamics. Fluctuations in supply and demand, drivers for oversupply/undersupply conditions, and what this means for profits.

Subsidies: why subsidize? how much to subsidize? role of PV in the global energy market.

Guest Lecture, Brendan Neagle - Modules and installations