Achieving strong absorption of low-energy photons is one of the key issues to demonstrate quantum dot solar cells working in the intermediate band regime at practical concentration factors and operating temperatures. Guided-mode resonance effects may enable large enhancement of quantum dot intraband optical transitions. We propose quantum dot thin-film cells designed to have significant field waveguiding in the quantum dot stack region and patterned at the rear-side with a sub-wavelength diffraction grating. Remarkable increase of the optical path length at mid-infrared wavelengths is shown owing to guided-mode resonances. Design guidelines are presented for energy and strength of the second-photon absorption for III-V quantum dots, such as InAs/GaAs and GaSb/GaAs, whose intraband and intersubband transitions roughly extends over the 2 − 8 µm range. The proposed design can also be applied to quantum dot infrared detectors. Angle-selectivity is discussed in view of applications in concentrator photovoltaic systems and infrared imaging systems.
Guided-mode resonance gratings for enhanced mid-infrared absorption in quantum dot intermediate-band solar cells / Elsehrawy, Farid; Niemi, Tapio; Cappelluti, Federica. - In: OPTICS EXPRESS. - ISSN 1094-4087. - ELETTRONICO. - 26:6(2018), pp. A352-A359. [10.1364/OE.26.00A352]
|Titolo:||Guided-mode resonance gratings for enhanced mid-infrared absorption in quantum dot intermediate-band solar cells|
|Data di pubblicazione:||2018|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1364/OE.26.00A352|
|Appare nelle tipologie:||1.1 Articolo in rivista|