Light down-conversion with over 100% external quantum efficiency in bulk germanium

Autor:	V. K. Malyutenko, V. V. Bogatyrenko
Rok vydání:	2012
Předmět:	Materials science Photon Physics and Astronomy (miscellaneous) business.industry Energy conversion efficiency chemistry.chemical_element Germanium Wavelength chemistry Atomic electron transition Emissivity Optoelectronics Quantum efficiency Free carrier absorption business
Zdroj:	Applied Physics Letters. 101:081111
ISSN:	1077-3118 0003-6951
Popis:	To bypass indirect bandstructure limitations in Ge and have it effectively emitting, we employ light down conversion process at elevated temperatures (emissivity enhancement technique). By applying short wavelength pump light (λin, interband electron transitions), we enhance thermal emission output in the spectral range of intraband electron transitions (λout, free carrier absorption band). We experimentally realized conditions (λin = 1.9 μm, λout = 2–25 μm, T = 380 K) when Ge wafers demonstrated power conversion efficiency of 21% and external quantum efficiency (photon multiplication coefficient) of 130%. Advantages of Ge over Si and ways to realize Ge-based radiative cooler are discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::17086801fe49b137884249dcd5fdd59e https://doi.org/10.1063/1.4748362 Zobrazit plný text záznamu