solar cell

solar cell
Unknown authorUnknown author · Public domain · source
Name	Solar cell
Invented	1839
Inventor	Edmond Becquerel
Applications	Photovoltaic power, Spacecraft, Consumer electronics

solar cell A device that converts light into electricity by the photovoltaic effect, a solar cell is central to technologies deployed by NASA, European Space Agency, Siemens, General Electric, and Tesla, Inc. for terrestrial and extraterrestrial power generation. Prominent demonstration projects such as Nellis Solar Power Plant, Ivanpah Solar Power Facility, Desertec, Cadarache research center, and national programs in Germany, China, United States, India, and Japan illustrate its role in energy transitions led by institutions like International Energy Agency and United Nations initiatives.

Overview

Solar cells form the basic building block of photovoltaic modules used by utilities like Iberdrola and EDF and by governments such as California Energy Commission and Ministry of New and Renewable Energy (India). Commercial markets are dominated by manufacturers including LONGi Green Energy, Trina Solar, First Solar, JinkoSolar, and REC Group. Research institutions such as Massachusetts Institute of Technology, Fraunhofer ISE, National Renewable Energy Laboratory, Chinese Academy of Sciences, and École Polytechnique advance cell architectures that feed into supply chains involving Shenzhen, Taiwan Semiconductor Manufacturing Company, Kyocera, and Panasonic Corporation.

History

Early observations of photovoltaic effects by Alexandre-Edmond Becquerel in 1839 were followed by development milestones tied to industrial players and national programs including Bell Labs’ 1954 silicon cell, Cold War-era satellite programs by NASA and the Soviet space program, and commercial scale-up in the 1970s associated with oil crises affecting OPEC policy. Policy drivers such as feed-in tariffs in Germany and incentives under the Energy Policy Act of 2005 in the United States accelerated deployment alongside corporate adoption by Walmart and Google. Landmark demonstrations include deployments at Hedging Islands and research breakthroughs at Stanford University, University of New South Wales, and IBM Research.

Principles and Operation

Operation relies on the photovoltaic effect first explored in experiments at institutions like Collège de France and later formalized in semiconductor physics by scientists affiliated with Bell Labs and Harvard University. Photons from the Sun excite charge carriers across a p–n junction in materials investigated at Max Planck Institute for Solid State Research and Rensselaer Polytechnic Institute, generating current directed by metal contacts patterned using techniques developed at Intel and Texas Instruments. Performance metrics used by regulators and utilities including Federal Energy Regulatory Commission and Ofgem reference standards set by International Electrotechnical Commission and testing by Underwriters Laboratories.

Materials and Types

Materials range from crystalline silicon produced by firms like Wacker Chemie and GCL-Poly to thin films developed by First Solar (cadmium telluride) and perovskites studied at Oxford University and Seoul National University. Emerging types include organic photovoltaics researched at Eindhoven University of Technology and dye-sensitized cells pioneered by teams at University of Fribourg and EPFL. Tandem architectures combine technologies advanced at University of Toronto and Northwestern University, while concentrator photovoltaics involve optics influenced by companies such as Soitec and projects at Sandia National Laboratories.

Manufacturing and Fabrication

Fabrication processes involve wafering, dopant diffusion, metallization, and encapsulation executed in fabs run by Applied Materials, ASML, and Lam Research. Thin-film deposition uses sputtering and chemical vapor deposition with equipment from Veeco Instruments and Tokyo Electron. Supply chains link polysilicon suppliers like Hemlock Semiconductor to module assemblers in hubs such as Zhangjiakou and Dongguan. Certification and quality assurance rely on test protocols from PV Evolution Labs and standards from International Organization for Standardization.

Performance and Efficiency

Cell efficiency records tracked by organizations such as National Renewable Energy Laboratory and Japan Photovoltaic Energy Association show progression from early single-digit yields to multi-junction cells exceeding efficiencies demonstrated by teams at National Institute of Advanced Industrial Science and Technology, Fraunhofer ISE, and Sharp Corporation. Metrics including fill factor, open-circuit voltage, and temperature coefficients are used by utilities like PG&E and grid operators including CAISO to model output variability. Degradation studies are performed by Sandia National Laboratories and lifecycle assessments by European Commission programs.

Applications and Integration

Applications span rooftop systems installed by companies such as Sunrun and Sunnova Energy to utility-scale arrays developed by NextEra Energy and Enel. Spacecraft and satellites from SpaceX and Lockheed Martin use high-efficiency cells by contractors including Boeing and Ball Aerospace. Building-integrated photovoltaics are promoted by standards from LEED and projects showcased by Times Square redevelopment and the One Central Park complex. Microgrids and off-grid systems are deployed in programs funded by World Bank and implemented by NGOs like SolarAid in regions governed by authorities in Kenya and Bangladesh.

Environmental Impact and Recycling

Environmental assessments by United Nations Environment Programme and Organisation for Economic Co-operation and Development evaluate lifecycle emissions of panels produced by manufacturers such as Canadian Solar and Hanwha Q CELLS. Recycling initiatives involve firms like First Solar and programs under directives from the European Parliament and California Energy Commission aiming to recover silicon, silver, and rare elements. Hazard mitigation for materials like cadmium is managed under regulations from Environmental Protection Agency and European Chemicals Agency while end-of-life policy frameworks are developed by agencies including Department of Energy (United States).

Category:Photovoltaics