Can quantum coherent solar cells break detailed balance?
Carefully engineered coherent quantum states have been proposed as a design attribute that is hypothesized to enable solar photovoltaic cells to break the detailed balance (or radiative) limit of power conversion efficiency by possibly causing radiative recombination to be suppressed. However, in full compliance with the principles of statistical mechanics and the laws of thermodynamics, specially prepared coherent quantum states do not allow a solar photovoltaic cell—a quantum threshold energy conversion device—to exceed the detailed balance limit of power conversion efficiency. At the condition given by steady-state open circuit operation with zero nonradiative recombination, the photon absorption rate (or carrier photogeneration rate) must balance the photon emission rate (or carrier radiative recombination rate) thus ensuring that detailed balance prevails. Quantum state transitions, entropy-generating hot carrier relaxation, and photon absorption and emission rate balancing are employed holistically and self-consistently along with calculations of current density, voltage, and power conversion efficiency to explain why detailed balance may not be violated in solar photovoltaic cells.
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)
- Publication Date:
- OSTI Identifier:
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; COMPLIANCE; CONVERSION; CURRENT DENSITY; DESIGN; EFFICIENCY; ELECTRIC POTENTIAL; ENGINEERS; ENTROPY; LAWS; OPERATION; PHOTON EMISSION; PHOTONS; QUANTUM STATES; RECOMBINATION; RELAXATION; SOLAR CELLS; STATISTICAL MECHANICS; STEADY-STATE CONDITIONS; THERMODYNAMICS; THRESHOLD ENERGY