4 research outputs found
Efficiency Enhancement of Silicon Heterojunction Solar Cells via Photon Management Using Graphene Quantum Dot as Downconverters
By
employing graphene quantum dots (GQDs), we have achieved a high
efficiency of 16.55% in n-type Si heterojunction solar cells. The
efficiency enhancement is based on the photon downconversion phenomenon
of GQDs to make more photons absorbed in the depletion region for
effective carrier separation, leading to the enhanced photovoltaic
effect. The short circuit current and the fill factor are increased
from 35.31 to 37.47 mA/cm<sup>2</sup> and 70.29% to 72.51%, respectively.
The work demonstrated here holds the promise for incorporating graphene-based
materials in commercially available solar devices for developing ultrahigh
efficiency photovoltaic cells in the future
Si Hybrid Solar Cells with 13% Efficiency <i>via</i> Concurrent Improvement in Optical and Electrical Properties by Employing Graphene Quantum Dots
By
employing graphene quantum dots (GQDs) in PEDOT:PSS, we have
achieved an efficiency of 13.22% in Si/PEDOT:PSS hybrid solar cells.
The efficiency enhancement is based on concurrent improvement in optical
and electrical properties by the photon downconversion process and
the improved conductivity of PEDOT:PSS via appropriate incorporation
of GQDs. After introducing GQDs into PEDOT:PSS, the short circuit
current and the fill factor of rear-contact optimized hybrid cells
are increased from 32.11 to 36.26 mA/cm<sup>2</sup> and 62.85% to
63.87%, respectively. The organicâinorganic hybrid solar cell
obtained herein holds the promise for developing photon-managing,
low-cost, and highly efficient photovoltaic devices
Above-11%-Efficiency OrganicâInorganic Hybrid Solar Cells with Omnidirectional Harvesting Characteristics by Employing Hierarchical Photon-Trapping Structures
Hierarchical
structures consisting of micropyramids and nanowires
are used in Si/PEDOT:PSS hybrid solar cells to achieve a power conversion
efficiency (PCE) up to 11.48% with excellent omnidirectionality. The
structure provides a combined concepts of superior light trapping
ability, significant increase of pân junction areas, and short
carrier diffusion distance, improving the photovoltaic characteristics
including short-circuit current density, fill factor, and PCE. The
enhancement of power generation is up to 253.8% at high incident angles,
showing the outstanding omnidirectional operation ability of hybrid
cells with hierarchical Si surfaces. This properly designed hierarchical-structured
device paves a promising way for developing low-cost, high-efficiency,
and omnidirectional solar applications in the future
Realizing High-Efficiency Omnidirectional nâType Si Solar Cells <i>via</i> the Hierarchical Architecture Concept with Radial Junctions
Hierarchical structures combining micropyramids and nanowires with appropriate control of surface carrier recombination represent a class of architectures for radial p-n junction solar cells that synergizes the advantageous features including excellent broad-band, omnidirectional light-harvesting and efficient separation/collection of photoexcited carriers. The heterojunction solar cells fabricated with hierarchical structures exhibit the efficiency of 15.14% using cost-effective as-cut Czochralski n-type Si substrates, which is the highest reported efficiency among all n-type Si nanostructured solar cells. We also demonstrate the omnidirectional solar cell that exhibits the daily generated power enhancement of 44.2% by using hierarchical structures, as compared to conventional micropyramid control cells. The concurrent improvement in optical and electrical properties for realizing high-efficiency omnidirectional solar cells using as-cut Czochralski n-type Si substrates demonstrated here makes a hierarchical architecture concept promising for large-area and cost-effective mass production