Structure, transport and photoconductance of PbS quantum dot monolayers functionalized with a copper phthalocyanine derivative

Abstract

CopyrightOther than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policyPlease contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. We simultaneously surface-functionalize PbS nanocrystals with Cu 4,4',4'',4'''-tetraaminophthalocyanine and assemble this hybrid material into macroscopic monolayers. Electron microscopy and X-ray scattering reveal a granular mesocrystalline structure with strong coherence between the atomic lattice and the superlattice of nanocrystals within each domain. Terahertz spectroscopy and field-effect transistor measurements indicate efficient coupling of holes throughout the hybrid thin film, in conjunction with a pronounced photoresponse. We demonstrate the potential of this material for optoelectronic applications by fabricating a light-effect transistor . This work is downloaded from

Quantum Dot Solar Cells: Small Beginnings Have Large Impacts

“…Further ordering of the QDs into a superlattice has also shown up to 5 fold enhancement of the absorption and represents a potential method to improving device properties as we discuss in the final section [68,69]. Other strategies include hybrid structures between organic conductors and QDs, as discussed elsewhere [70][71][72][73].…”

Tunable Charge Transport in Hybrid Superlattices of Indium Tin Oxide Nanocrystals and Metal Phthalocyanines—Toward Sensing Applications

“…It is worth pointing out that the lowest sheet resistance of the sample (observed for ITO/Cu4APc thin‐film) is on the order of MΩ which is larger than any expected contact resistance. Furthermore, previously we have shown using the transmission line method that the effect of contact resistance in our system is negligible, thus, a two‐point measurement is appropriate in this experiment …”

Structure–Transport Correlation Reveals Anisotropic Charge Transport in Coupled PbS Nanocrystal Superlattices

“…[ 22 ] This results in long‐range ordered and highly conductive SLs, since the rigid and relatively long ligands reduce the energy barrier for charge transport without deteriorating structural order, as it was shown previously. [ 23,24 ] Hence, the hybrid system of PbS NCs and Cu4APc is an ideal compromise between increased electronic coupling and long‐range ordered SLs, which was a fundamental prerequisite for this study. By means of soft‐lithographic microcontact printing, [ 25 ] we transfer stripes of PbS NC‐Cu4APc SLs with a width ( W ) of roughly 4 µm onto trenches of ≈1 µm length ( L ) between two gold contacts on X‐ray transparent Kapton and Si/SiO x substrates.…”

“…Using Si/SiO x as substrate, we performed field‐effect transistor measurements of the PbS NC‐Cu4APc SLs, revealing p‐type behavior, which agrees with our previous study (Figure S3, Supporting Information). [ 23 ] The microchannels show hole‐mobilities up to μ ≈ 10 −4 cm 2 V −1 s −1 . Based on these transport properties and previous reports on the importance of mid‐gap states in PbS NC materials, we believe that transport in the present material occurs predominantly via hopping through trap states close to the valence eigenstate (the 1S h state).…”