Theory of photovoltaic characteristics of semiconductor quantum dot solar cells

Journal Article · Sun Aug 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4961046· OSTI ID:22598877

Wu, Yuchang ^[1]

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1. Low Carbon Energy Institute, China University of Mining and Technology, Xuzhou 221116 (China)

We develop a comprehensive rate equations model for semiconductor quantum dot solar cells (QDSCs). The model is based on the continuity equations with a proper account for quantum dots (QDs). A general analytical expression for the total current density is obtained, and the current-voltage characteristic is studied for several specific situations. The degradation in the open circuit voltage of the QDSC is shown to be due to strong spontaneous radiative recombination in QDs. Due to small absorption coefficient of the QD ensemble, the improvement in the short circuit current density is negligible if only one QD layer is used. If spontaneous radiative recombination would be suppressed in QDs, a QDSC with multiple QD layers would have significantly higher short circuit current density and power conversion efficiency than its conventional counterpart. The effects of photoexcitation of carriers from discrete-energy states in QDs to continuum-energy states are discussed. An extended model, which includes excited states in QDs, is also introduced.

• OSTI ID: 22598877
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
CONTINUITY EQUATIONS
CURRENT DENSITY
ELECTRIC POTENTIAL
ELECTRICAL FAULTS
EXCITED STATES
LAYERS
PHOTOVOLTAIC EFFECT
QUANTUM DOTS
REACTION KINETICS
RECOMBINATION
SEMICONDUCTOR MATERIALS
SOLAR CELLS