Journal ArticleDOI
The dominant role of exciton quenching in PbS quantum-dot-based photovoltaic devices.
Reads0
Chats0
TLDR
It is found that the effective density of trapped carriers ranges from 1 in 10 to 2 in 10,000 quantum dots, depending on ligand treatment, and that nonradiative exciton quenching, as opposed to recombination with trapped carriers, is likely the limiting mechanism in PbS-quantum-dot-based photovoltaic devices.Abstract:
We present a quantitative measurement of the number of trapped carriers combined with a measurement of exciton quenching to assess limiting mechanisms for current losses in PbS-quantum-dot-based photovoltaic devices. We use photocurrent intensity dependence and short-wave infrared transient photoluminescence and correlate these with device performance. We find that the effective density of trapped carriers ranges from 1 in 10 to 1 in 10 000 quantum dots, depending on ligand treatment, and that nonradiative exciton quenching, as opposed to recombination with trapped carriers, is likely the limiting mechanism in these devices.read more
Citations
More filters
Journal ArticleDOI
Pathways for solar photovoltaics
TL;DR: In this article, the authors examine potential limits to PV deployment at the terawatt scale, emphasizing constraints on the use of commodity and PV-critical materials, and propose material complexity as a guiding framework for classifying PV technologies.
Journal ArticleDOI
Open-Circuit Voltage Deficit, Radiative Sub-Bandgap States, and Prospects in Quantum Dot Solar Cells
Chia-Hao Marcus Chuang,Andrea Maurano,Riley E. Brandt,Gyu Weon Hwang,Joel Jean,Tonio Buonassisi,Vladimir Bulovic,Moungi G. Bawendi +7 more
TL;DR: It is concluded that eliminating sub-bandgap states in PbS QD films has the potential to show a greater gain than may be attainable by optimization of interfaces between QDs and other materials.
Journal ArticleDOI
Subdiffusive Exciton Transport in Quantum Dot Solids
Gleb M. Akselrod,Ferry Prins,Lisa V. Poulikakos,Elizabeth M. Y. Lee,Mark C. Weidman,A. Jolene Mork,Adam P. Willard,Vladimir Bulovic,William A. Tisdale +8 more
TL;DR: It is found that the exciton diffusion length, which exceeds 30 nm in some cases, can be tuned by adjusting the inorganic shell thickness and organic ligand length, offering a powerful strategy for controlling exciton movement.
Journal ArticleDOI
Speed Limit for Triplet-Exciton Transfer in Solid-State PbS Nanocrystal-Sensitized Photon Upconversion.
Lea Nienhaus,Mengfei Wu,Nadav Geva,James J. Shepherd,Mark W. Wilson,Vladimir Bulovic,Troy Van Voorhis,Marc A. Baldo,Moungi G. Bawendi +8 more
TL;DR: This work studies the transfer of excitons from colloidal lead sulfide nanocrystals to the spin-triplet state of rubrene molecules by reducing the length of the carboxylic acid ligands on the nanocrystal surface, and thinning the effective ligand shell to increase the characteristic transfer rate.
Journal ArticleDOI
In Situ Passivation for Efficient PbS Quantum Dot Solar Cells by Precursor Engineering.
Yongjie Wang,Kunyuan Lu,Lu Han,Zeke Liu,Guozheng Shi,Hong-Hua Fang,Si Chen,Tian Wu,Fan Yang,Mengfan Gu,Sijie Zhou,Xufeng Ling,Xun Tang,Jiawei Zheng,Maria Antonietta Loi,Wanli Ma +15 more
TL;DR: For the first time, systematic investigations are carried out on the effect of lead precursor engineering on the device performance and it is revealed that acetate can act as an efficient capping ligands together with oleic acid, providing better surface coverage and replace some of the harmful hydroxyl ligands during the synthesis.
References
More filters
Journal ArticleDOI
Hybrid passivated colloidal quantum dot solids
Alexander H. Ip,Susanna M. Thon,Sjoerd Hoogland,Oleksandr Voznyy,David Zhitomirsky,Ratan Debnath,Larissa Levina,Lisa R. Rollny,Graham H. Carey,Armin Fischer,Kyle W. Kemp,Illan J. Kramer,Zhijun Ning,André J. Labelle,Kang Wei Chou,Aram Amassian,Edward H. Sargent +16 more
TL;DR: The density of midgap trap states in CQD solids is quantified and shown to be limited by electron-hole recombination due to these states, and a robust hybrid passivation scheme is developed that can passivate trap sites that are inaccessible to much larger organic ligands.
Journal ArticleDOI
Dependence of carrier mobility on nanocrystal size and ligand length in PbSe nanocrystal solids.
Yao Liu,Markelle Gibbs,James Puthussery,Steven J. Gaik,Rachelle Ihly,Hugh W. Hillhouse,Matt Law +6 more
TL;DR: The results establish a baseline for mobility trends in PbSe NC solids, with implications for fabricating high-mobility NC-based optoelectronic devices, and find that carrier mobility is independent of the polydispersity of the NC samples, which can be understood if percolation networks of the larger-diameter, smaller-band-gap NCs carry most of the current in these NCsolids.
Journal ArticleDOI
Slow electron cooling in colloidal quantum dots.
TL;DR: It is found that relaxation is markedly slowed with increasing ZnSe shell thickness, which could prove useful for more efficient photovoltaic or infrared devices.
Journal ArticleDOI
Ligand Effects on Optical Properties of CdSe Nanocrystals
TL;DR: The complex of trioctylphosphine with Se atoms on the surface of CdSe NCs is found responsible for the trap emission band that is red-shifted relative to the photoluminescence band edge.
Journal ArticleDOI
Colloidal PbS Quantum Dot Solar Cells with High Fill Factor
Ni Zhao,Timothy P. Osedach,Timothy P. Osedach,Liang-Yi Chang,Scott M. Geyer,Darcy D. Wanger,Maddalena Binda,Alexi C. Arango,Moungi G. Bawendi,Vladimir Bulovic +9 more
TL;DR: A consistent mechanism for device operation is developed through a circuit model and experimental measurements, shedding light on new approaches for optimization of solar cell performance by modifying the interface between the QDs and the neighboring charge transport layers.