Hot carrier relaxation and inhibited thermalization in superlattice heterostructures: The potential for phonon management
- CNRS-Institute Photovoltaïque d'Ile de France (IPVF), Palaiseau (France)
- University of Oklahoma, Norman, OK (United States). Department of Physics and Astronomy
- University of Oklahoma, Norman, OK (United States). School of Aerospace and Mechanical Engineering
- CNRS-Institute Photovoltaïque d'Ile de France (IPVF), Palaiseau (France); CNRS-Ecole Polytechnique, Palaiseau (France)
- CNRS-Institute Photovoltaïque d'Ile de France (IPVF), Palaiseau (France); CNRS-Ecole Polytechnique, Palaiseau (France)
One of the main loss mechanisms in photovoltaic solar cells is the thermalization of photogenerated hot carriers via phonon-mediated relaxation. By inhibiting these relaxation mechanisms and reducing thermalization losses it may be possible to improve the power conversion efficiency of solar cells beyond the single gap limit. Here, type-II InAs/AlAsSb multi-quantum well structures are investigated to study the impact of the phononic properties of the AlAsSb barrier material in hot carrier thermalization. Experimental and theoretical results show that by increasing the barrier thickness (increasing the relative contribution of AlAsSb content in the superlattices), that the relaxation of hot carriers is reduced as observed in power- dependent photoluminescence and thermalization analysis. This is attributed to an increase in the phononic band gap of the MQW with increasing AlAsSb composition reducing the efficiency of the dominant Klemens mechanism as the phononic properties shift towards a more AlSb-like behavior.
- Research Organization:
- Univ. of Oklahoma, Norman, OK (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; National Science Foundation (NSF); USDOE
- Grant/Contract Number:
- SC0019384; ANR-IEED-002-02; ANR-19-CE05-0019; 1847129
- OSTI ID:
- 1853165
- Alternate ID(s):
- OSTI ID: 1784790; OSTI ID: 1987851
- Journal Information:
- Applied Physics Letters, Vol. 118, Issue 21; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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