Quantum Dot Photovoltaics in the Extreme Quantum Confinement Regime: The Surface-Chemical Origins of Exceptional Air- and Light-Stability

Tang, Jiang; Brzozowski, Lukasz; Barkhouse, D. Aaron R.; Wang, Xihua; Debnath, Ratan; Wolowiec, Remigiusz; Palmiano, Elenita; Levina, Larissa; Pattantyus-Abraham, Andras G.; Jamakosmanovic, Damir; Sargent, Edward H.

doi:10.1021/nn901564q

Cited by 353 publications

(417 citation statements)

References 35 publications

Supporting

Mentioning

391

Contrasting

Order By: Relevance

“…However, the spatial separation induced by the long oleic acid (OA) ligand that was used to cap QDs34 probably degrade the charge transfer between QDs and NWs. Therefore, it is necessary to exchange the long ligand with short one, such as EDT, tetrabutyl ammonium iodide (TBAI) 35, 36, 37, 38. Herein, 1–2 mL EDT solution was dropped on the device to replace the long ligand of OA for about 2–3 min, see the schematic illustration in Figure 1c.…”

Section: Resultsmentioning

confidence: 99%

An Enhanced UV–Vis–NIR an d Flexible Photodetector Based on Electrospun ZnO Nanowire Array/PbS Quantum Dots Film Heterostructure

et al. 2016

View full text Add to dashboard Cite

ZnO nanostructure‐based photodetectors have a wide applications in many aspects, however, the response range of which are mainly restricted in the UV region dictated by its bandgap. Herein, UV–vis–NIR sensitive ZnO photodetectors consisting of ZnO nanowires (NW) array/PbS quantum dots (QDs) heterostructures are fabricated through modified electrospining method and an exchanging process. Besides wider response region compared to pure ZnO NWs based photodetectors, the heterostructures based photodetectors have faster response and recovery speed in UV range. Moreover, such photodetectors demonstrate good flexibility as well, which maintain almost constant performances under extreme (up to 180°) and repeat (up to 200 cycles) bending conditions in UV–vis–NIR range. Finally, this strategy is further verified on other kinds of 1D nanowires and 0D QDs, and similar enhancement on the performance of corresponding photodetecetors can be acquired, evidencing the universality of this strategy.

show abstract

Section: Resultsmentioning

confidence: 99%

An Enhanced UV–Vis–NIR an d Flexible Photodetector Based on Electrospun ZnO Nanowire Array/PbS Quantum Dots Film Heterostructure

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Understanding the surface of QDs is a key to further advance solar cells in both performance and stability 11,[16][17][18] .…”

Section: Icrea-institució Catalana De Recerca I Estudis Avançats Llumentioning

confidence: 99%

The role of surface passivation for efficient and photostable PbS quantum dot solar cells

et al. 2016

View full text Add to dashboard Cite

For any emerging photovoltaic technology to become commercially relevant, both its power conversion efficiency and photostability are key parameters to be fulfilled. Colloidal quantum dot solar cells are a solution-processed, low-cost technology that has reached efficiency about 9% by judiciously controlling the surface of the quantum dots to enable surface passivation and tune energy levels. However, the role of quantum dot's surface on the stability of these solar cells has remained elusive. Here we report on highly efficient and photostable quantum dot solar cells with efficiencies of 9.6% (and independently certificated values of 8.7%). As a result of optimised surface passivation and suppression of hydroxyl ligands-which are found to be detrimental for both efficiency and photostability-the efficiency remains within 80% after

show abstract

“…We need to note that prolonged oxidation of PbS QDs results in the formation of various oxide species such as PbSO 3 and PbSO 4 . 41 In that case the simple vacancy and impurity defect picture is not sufficient to describe the electronic structure of the QD, since the composition is significantly modified.…”

Section: Spectroscopic Evidence and Further Theoretical Support On Thmentioning

confidence: 99%

Molecular Oxygen Induced in-Gap States in PbS Quantum Dots

Zhang

Zherebetskyy

Bronstein³

et al. 2015

ACS Nano

View full text Add to dashboard Cite

Artificial solids composed of semiconductor quantum dots (QDs) are being developed for large-area electronic and optoelectronic applications, but these materials often have defect-induced in-gap states (IGS) of unknown chemical origin.Here we performed scanning probe based spectroscopic analysis and density functional theory calculations to determine the nature of such states and their electronic structure. We found that IGS near the valence band occur frequently in the QDs except when treated with reducing agents. Calculations on various possible defects and chemical spectroscopy revealed that molecular oxygen is most likely at the origin of these IGS. We expect this impurity-induced deep IGS to be a common occurrence in ionic semiconductors, where the intrinsic vacancy defects either do not produce IGS or produce shallow states near band edges. Ionic QDs with surface passivation to block impurity adsorption are thus ideal for highefficiency optoelectronic device applications.

show abstract

Quantum Dot Photovoltaics in the Extreme Quantum Confinement Regime: The Surface-Chemical Origins of Exceptional Air- and Light-Stability

Cited by 353 publications

References 35 publications

An Enhanced UV–Vis–NIR an d Flexible Photodetector Based on Electrospun ZnO Nanowire Array/PbS Quantum Dots Film Heterostructure

An Enhanced UV–Vis–NIR an d Flexible Photodetector Based on Electrospun ZnO Nanowire Array/PbS Quantum Dots Film Heterostructure

The role of surface passivation for efficient and photostable PbS quantum dot solar cells

Molecular Oxygen Induced in-Gap States in PbS Quantum Dots

Contact Info

Product

Resources

About