Rare earth garnet selective emitter

Conference · Thu Sep 01 04:00:00 EDT 1994

OSTI ID:36442

Lowe, R A; Chubb, D L; Farmer, S C; Good, B S ^[1]

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1. Kent State Univ., OH (United States)

Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon{sub {lambda}}) approximately equal to 0.74, ((4)l{sub 15/2}) - ((4)l{sub 13/2}), for Er-YAG and epsilon{sub {lambda}} approximately equal to 0.65, ((5)l{sub 7})-((5)l{sub 8}) for (Ho-YAG) at excellent candidates for high efficiency selective emitters in the thermophotovoltaics (TPV) systems operating at moderate temperatures (1200-1500K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper the authors present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. This paper presents normal spectral emittance, epsilon{sub {lambda}} measurements of holmium (Ho), and erbium (Er) doped YAG thin film selective emitters at 1500 K, and compares those results with the theoretical spectral emittance.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 36442
• Report Number(s): N--95-20502; NASA-CP--3278; E--9083; NAS--1.55:3278; CONF-9406314--
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
ALUMINIUM OXIDES
EMISSIVITY
ERBIUM ADDITIONS
FERRITE GARNETS
HOLMIUM ADDITIONS
PHOTOVOLTAIC CONVERSION
RADIANT HEAT TRANSFER
THIN FILMS
YTTRIUM COMPOUNDS