Matches in SemOpenAlex for { <https://semopenalex.org/work/W2788920818> ?p ?o ?g. }
Showing items 1 to 69 of
69
with 100 items per page.
- W2788920818 abstract "Furthering our understanding of next generation hight harvesting devices has the potential to revolutionise energy storage and production. This thesis discusses the use of science techniques, principally soft X-ray photoelectron spectroscopies, to study two types of molecular solar cell: dye sensitised solar cells and organic photovoltaic devices. Much of this work relies on electrospray deposition, which is becoming a well established technique allowing the in-situ deposition of fragile, non-volatile molecules in high vacuum environments. This thesis explores the potential use of electrospray deposition to build model photovoltaic devices, including bi-layer and bulk heterojucntion structures, to extend the use of the technique beyond the simple on a surface type of experiment that have previously dominated the high-vacuum electrospray deposition literature.Firstly this thesis presents the development of two instruments that aim to aid the characterisation of electrospray. A novel ultra-fast exposure microscopy system is presented that used a pulsed laser and purpose-designed cell containing a fluorescent dye to produce short (<20 ns) incoherent light pulses. Images of electrospray ionisation, highlighting the capabilities of the imaging system, are presented. Preliminary images showing the unusual behaviour when the liquid properties are severely changed by adding a high concentration of salt are also presented. We also include some proof-of-concept data, collected using a home-built image charge detection instrument, to measure velocity distributions of molecular ions that are landing on the surface. This instrument has led the way to a more refined image charge detection instrument that will be of great benefit to future studies.A series of three experiments are presented that highlight the capability and suitability of high vacuum deposition to produce the types of structures used in molecular photovoltaic devices. Time of flight secondary ion mass spectrometry was used to image a bi-layer structure, produced using electrospray from two molecules dissolved in the same solvent, showing there is little mixing between the layers. These structures are challenging to make using processes like spin casting where solvent compatibility results in mixing of the films. Two electrospray sources were used to co-deposit two molecules simultaneously from immiscible solvents, which is again not possible using standard techniques. Finally a complex polymer blend was deposited using electrospray, from a single solution, and analysed using X-ray photoelectron spectroscopy (XPS) finding evidence of preferential deposition of one species.Bi-isonicotionic acid (the ligand of many popular organometallic photo-sensitisers) has been deposited onto Ag(111) in-situ via sublimation. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) have been used to obtain chemical information and map out the density of states for the system. We find the LUMO (lowest unoccupied molecular orbital) lies below the Fermi level of the silver allowing ultra-fast bi-directional charge transfer between the molecule and surface. This was probed using resonant photoelectron spectroscopy (RPES) by observation of super-spectator and super-Auger decay mechanisms from the core excited state.In the final experimental chapter, films of phenyl-C61-butyric acid methyl ester (PCBM) and Poly(3-hexylthiophene-2,5-diyl) (P3HT), common acceptor and donor molecules used in organic photovoltaic devices, were successfully deposited in-situ in UHV using electrospray deposition on the Au(111) surface. Bi-layer heterojunction and bulk heterojunction structures of the two molecules were also produced using electrospray. Again, XPS, XAS and RPES were used to investigate chemical interactions, map out the density of states for the molecular systems and probe charge transfer between the molecules and surfaces. For PCBM, some interesting chemical behaviour regarding an oxygen group on the ligand is observed. Measurements also show the LUMO of PCBM lies below the Fermi level, but surprisingly no evidence of super-spectator or super-Auger decay is found. RPES was unable to show evidence of charge transfer between the two molecules in a bi-layer heterojunction structure. Finally, careful ionisation potential calibration of XPS spectra were used to try and infer the position of the valence band maximum of the two molecules when brought together in a heterojunction." @default.
- W2788920818 created "2018-03-06" @default.
- W2788920818 creator A5080012269 @default.
- W2788920818 date "2017-12-14" @default.
- W2788920818 modified "2023-09-24" @default.
- W2788920818 title "Complex molecules on surfaces : in-situ electrospray deposition and photoelectron spectroscopy" @default.
- W2788920818 hasPublicationYear "2017" @default.
- W2788920818 type Work @default.
- W2788920818 sameAs 2788920818 @default.
- W2788920818 citedByCount "0" @default.
- W2788920818 crossrefType "dissertation" @default.
- W2788920818 hasAuthorship W2788920818A5080012269 @default.
- W2788920818 hasConcept C107872376 @default.
- W2788920818 hasConcept C113196181 @default.
- W2788920818 hasConcept C127413603 @default.
- W2788920818 hasConcept C145148216 @default.
- W2788920818 hasConcept C151730666 @default.
- W2788920818 hasConcept C171250308 @default.
- W2788920818 hasConcept C175708663 @default.
- W2788920818 hasConcept C178790620 @default.
- W2788920818 hasConcept C185592680 @default.
- W2788920818 hasConcept C192562407 @default.
- W2788920818 hasConcept C194451485 @default.
- W2788920818 hasConcept C2816523 @default.
- W2788920818 hasConcept C42360764 @default.
- W2788920818 hasConcept C64297162 @default.
- W2788920818 hasConcept C86803240 @default.
- W2788920818 hasConceptScore W2788920818C107872376 @default.
- W2788920818 hasConceptScore W2788920818C113196181 @default.
- W2788920818 hasConceptScore W2788920818C127413603 @default.
- W2788920818 hasConceptScore W2788920818C145148216 @default.
- W2788920818 hasConceptScore W2788920818C151730666 @default.
- W2788920818 hasConceptScore W2788920818C171250308 @default.
- W2788920818 hasConceptScore W2788920818C175708663 @default.
- W2788920818 hasConceptScore W2788920818C178790620 @default.
- W2788920818 hasConceptScore W2788920818C185592680 @default.
- W2788920818 hasConceptScore W2788920818C192562407 @default.
- W2788920818 hasConceptScore W2788920818C194451485 @default.
- W2788920818 hasConceptScore W2788920818C2816523 @default.
- W2788920818 hasConceptScore W2788920818C42360764 @default.
- W2788920818 hasConceptScore W2788920818C64297162 @default.
- W2788920818 hasConceptScore W2788920818C86803240 @default.
- W2788920818 hasLocation W27889208181 @default.
- W2788920818 hasOpenAccess W2788920818 @default.
- W2788920818 hasPrimaryLocation W27889208181 @default.
- W2788920818 hasRelatedWork W1584146307 @default.
- W2788920818 hasRelatedWork W1621916526 @default.
- W2788920818 hasRelatedWork W1658487613 @default.
- W2788920818 hasRelatedWork W1972525870 @default.
- W2788920818 hasRelatedWork W1974005461 @default.
- W2788920818 hasRelatedWork W2077717114 @default.
- W2788920818 hasRelatedWork W2082606542 @default.
- W2788920818 hasRelatedWork W2092630570 @default.
- W2788920818 hasRelatedWork W2119197489 @default.
- W2788920818 hasRelatedWork W2119797797 @default.
- W2788920818 hasRelatedWork W2161433906 @default.
- W2788920818 hasRelatedWork W2188600113 @default.
- W2788920818 hasRelatedWork W2315294395 @default.
- W2788920818 hasRelatedWork W2399838821 @default.
- W2788920818 hasRelatedWork W2805556799 @default.
- W2788920818 hasRelatedWork W2913876298 @default.
- W2788920818 hasRelatedWork W2951140312 @default.
- W2788920818 hasRelatedWork W3010383979 @default.
- W2788920818 hasRelatedWork W3015755946 @default.
- W2788920818 hasRelatedWork W3044801618 @default.
- W2788920818 isParatext "false" @default.
- W2788920818 isRetracted "false" @default.
- W2788920818 magId "2788920818" @default.
- W2788920818 workType "dissertation" @default.