Growth and properties of A.sup.III./sup. B.sup.V./sup. QD structures for intermediate band solar cells

0447827 - FZÚ 2016 RIV NL eng J - Journal Article
Vyskočil, Jan - Gladkov, Petar - Petříček, Václav - Hospodková, Alice - Pangrác, Jiří
Growth and properties of A^III B^V QD structures for intermediate band solar cells.
Journal of Crystal Growth. Roč. 414, č. 172 (2015), s. 172-176. ISSN 0022-0248. E-ISSN 1873-5002
R&D Projects: GA ČR(CZ) GP14-21285P
Institutional support: RVO:68378271 ; RVO:67985882
Keywords : metalorganic vapor phase epitaxy * InAs/GaAs Quantum dots * GaAsSb Strain reducing layer * solar cells
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.462, year: 2015

Intermediate band solar cells theoretically offer a promising way to significantly increase cell efficiency compared to a single-junction solar cell. We focused on the preparation of antimony containing materials as a covering of QD layers. In this paper we discuss how the concentration gradient of GaAsSb strain reducing layers can influence the resulting optical properties of the solar cell structures. The main principle of the structure is that the absorption of light is achieved at QD excited states with better overlap of electron and hole wave functions. With fast relaxation of carriers to the ground state the electrons and holes are quickly spatially separated. Two different composition gradients of GaAsSb SRL were used for the solar cell structure. One or five quantum dot stacks were compared. The maximal PC increased approximately 17 times with increasing number of QD layers from 1 to 5. The results suggest high application potential of this structure for photovoltaics.
Permanent Link: http://hdl.handle.net/11104/0249601