High efficiency single crystal CdTe solar cells
Subtitle: November 19, 2009 -- January 31, 2011
By: Michael Carmody and Angelo Gilmore, EPIR Technologies
Contributors: Gilmore, Angelo; EPIR Technologies; National Renewable Energy Laboratory (U.S.)
Series: NREL/SR-5200-51380; NREL/SR -- 5200-51380.
Publisher: National Renewable Energy Laboratory
Published: 2011
Place of publication: Golden, CO
Language: eng
Format: [electronic resource] :
Number of pages: 43
Subjects: Photovoltaic power generation; Research; Solar cells; Design and construction; Cadmium telluride; Manufacturing processes
Other titles: High efficiency single crystal cadmium telluride solar cells
Description: The goal of the program was to develop single crystal CdTe-based top cells grown on Si solar cells as a platform for the subsequent manufacture of high efficiency tandem cells for CPV applications. The keys to both the single junction and the tandem junction cell architectures are the ability to grow high quality single-crystal CdTe and CdZnTe layers on p-type Si substrates, to dope the CdTe and CdZnTe controllably, both n and p-type, and to make low resistance ohmic front and back contacts. EPIR demonstrated the consistent molecular beam epitaxy (MBE) growth of CdTe/Si and CdZnTe/Si having high crystalline quality despite very large lattice mismatches; epitaxial CdTe/Si and CdZnTe/Si consistently showed state-of-the-art electron mobilities and good hole mobilities; bulk minority carrier recombination lifetimes of unintentionally p-doped CdTe and CdZnTe grown by MBE on Si were demonstrated to be consistently of order 100 ns or longer; desired n- and p-doping levels were achieved; solar cell series specific resistances <10 Ohm-cm2 were achieved; A single-junction solar cell having a state-of-the-art value of Voc and a unverified 16.4% efficiency was fabricated from CdZnTe having a 1.80 eV bandgap, ideal for the top junction in a tandem cell with a Si bottom junction.
Notes: Title from PDF title screen (NREL, viewed May 16, 2011).

"May 2011."

Prepared under Subcontract No. NEU-0-99010-12 DE-AC36-08GO28308 PV10.1199

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