Title :
Enhancing the Near-Infrared Spectral Response of Silicon Optoelectronic Devices via Up-Conversion
Author :
Richards, Bryce S. ; Shalav, Avi
Author_Institution :
Heriot-Watt Univ., Edinburgh
Abstract :
A silicon-based optoelectronic device that exhibits an enhanced response to subbandgap light is described. The device structure consists of a bifacial silicon solar cell with an up- converting (UC) layer attached to the rear. Erbium-doped sodium yttrium fluoride (NaY0.8F4 : Er0.2 3+) phosphors are the optically active centers responsible for the UC luminescence. The unoptimized device is demonstrated to respond effectively to wavelengths (lambda) in the range of 1480-1580 nm with an external quantum efficiency (EQE) of 3.4% occurring at 1523 nm at an illumination intensity of 2.4 W/cm2 (EQE = 1.4 times 10-2 cm2/W). An analysis of the optical losses reveals that the luminescence quantum efficiency (LQE) of the device is 16.7% at 2.4 W/cm2 of 1523-nm excitation (LQE = 7.0 times 10-2 cm2/W), while further potential device improvements indicate that an EQE of 14.0% (5.8 times 10-2 cm2/W) could be realistically achieved.
Keywords :
erbium; luminescence; optical wavelength conversion; optoelectronic devices; phosphors; sodium compounds; solar cells; yttrium compounds; NaYF4:Er3+ - System; UC luminescence; bifacial silicon solar cell; illumination intensity; luminescence quantum efficiency; near infrared spectral response; phosphors; silicon optoelectronic devices; subbandgap light; up-conversion; up-converting layer; wavelength 1480 nm to 1580 nm; Erbium; Lighting; Luminescence; Optical devices; Optical losses; Optoelectronic devices; Phosphors; Photovoltaic cells; Silicon; Yttrium; Luminescence; photovoltaics (PVs); silicon solar cells; up-conversion (UC);
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2007.903197
