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Title:THE MORPHOLOGY DEPENDENCE ON GROWTH PARAMETERS IN NANOSTRUCTURED SEMICONDUCTORS
Authors:ID Fanetti, Mattia (Mentor) More about this mentor... New window
ID Gunde, Miha (Author)
Files:.pdf Miha_Gunde.pdf (30,93 MB)
MD5: B679C41027FC2B2C5F0F14598C50D221
 
Language:English
Work type:Bachelor thesis/paper
Typology:2.11 - Undergraduate Thesis
Organization:FAN - Faculty of Applied Sciences
Abstract:Poly(3-hexylthiophene) (P3HT) is an organic semiconductor material that is widely studied in the photovoltaics and transistor fields of research. The polymer exhibits a relatively high charge carrier mobility when the molecules are ordered in a crystalline way. In this case the material exhibits a fibril-like morphology, which is usually studied by atomic force microscopy (AFM). Previous studies show that blending P3HT with graphene can further improve the charge carrier transport properties of the film. In this experiment, the scanning electron microscope (SEM) has been chosen, due to its practical aspects such as speed of operation and ease of use. Three sets of samples have been analyzed, containing films made of P3HT+graphene blends at different concentrations. The aims of the experiment are: i) to find good conditions for the observation of the morphology features of the film ii) to perform a morphological analysis of the surface of three sets of samples containing both pure P3HT, and P3HT+graphene blend, and possibly to highlight correlation between morpholgy and the charge transport properties. Surface analysis is done by detecting the secondary electron (SE) emission, which is sensitive to topographical features of the surface. Good observation conditions were established by coating the specimen with a thin layer of conductive coating, using a high energy beam (30 keV), and tilting the sample to an angle (30 ◦ ). In two out of three of the analyzed pure P3HT films, the presence of fibrilles indicated a possibly good charge mobility, which has been confirmed by electrical measurements using time-of-flight photoconductivity method (TOF). The presence of graphene has only slightly modified morphology of the film. Features of graphene flakes, which lie flat in the film, have been observed such as flake edges and folds. The flakes are homogeneously dispersed in the film without forming any connected network. TOF measurements have shown an increase in mobility of the charge carriers in the P3HT+graphene film.
Keywords:scanning electron microscope, organic semiconductor thin film, P3HT, graphene, morphology
Place of publishing:Nova Gorica
Year of publishing:2014
PID:20.500.12556/RUNG-2182 New window
COBISS.SI-ID:4591867 New window
NUK URN:URN:SI:UNG:REP:NY7IZEJN
Publication date in RUNG:01.12.2016
Views:8092
Downloads:174
Metadata:XML DC-XML DC-RDF
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GUNDE, Miha, 2014, THE MORPHOLOGY DEPENDENCE ON GROWTH PARAMETERS IN NANOSTRUCTURED SEMICONDUCTORS [online]. Bachelor’s thesis. Nova Gorica. [Accessed 26 March 2025]. Retrieved from: https://repozitorij.ung.si/IzpisGradiva.php?lang=eng&id=2182
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Secondary language

Language:Slovenian
Title:MORFOLOŠKA ODVISNOST POVRŠINE NANOSTRUKTURIRANIH POLPREVODNIKOV OD PARAMETROV RASTI
Abstract:Poli(3-heksiltiofen) (P3HT) je organski polprevodniški material, ki se uporablja v raziskavah na področju fotovoltaike in tranzistorjev. Kadar so molekule P3HT urejene v kristalne strukture, ima polimer relativno visoko mobilnost nosilcev naboja. V takem primeru material kaže vlaknasto morfologijo, ki se navadno določa s pomočcjo mikroskopa na atomsko silo (AFM). Študije kažejo, da lahko mešanje P3HT z grafenom še poveča mobilnost prostih nosilcev naboja. Za ta eksperiment je bil izbran vrstični elektronski mikroskop (SEM) zaradi njegovih praktičnih lastnosti kot sta hitrost delovanja in enostavna uporaba. Analizirani so bili trije seti vzorcev, narejeni s čistim P3HT, ter mešanico P3HT s grafenom pri različnih koncentracijah. Cilji eksperimenta so: i) poiskati dobre pogoje za opazovanje morfoloških značilnosti sloja, ii) analizirati morfologijo površine treh setov vzorcev, ki vsebujejo tako čisti P3HT, kot mešanico P3HT+grafen, ter pokazati morebitno povezavo med morfologijo sloja in transportom naboja. Analizo površine smo opravili z emisijo sekundarnih elektronov (SE), ki je občutljiva na topografske značilnosti površine. Ugotovili smo, da je za dobro opazovanje potrebno vzorec prekriti s tankim prevodnim slojem. Za analizo smo uporabili visokoenergetski žarek z energijo 30 keV, vzorec pa smo opazovali pod kotom 30 ◦ . V dveh izmed treh analiziranih slojev čistega P3HT smo opazili vlakna, ki kažejo na dobro mobilnost nosilcev naboja. Ta je bila potrjena z električimi meritvami časa preleta naboja. Prisotnost grafena je le malo spremenila morfologijo sloja. Opazili smo tudi značilne oblike grafenskih lusk, kot so robovi in pregibi. Luske so homogeno porazdeljene v sloju brez medsebojnih povezav. Meritve časa preleta so pokazale povišano mobilnost nosilcev naboja v sloju mešanice P3HT+grafen.
Keywords:vrstični elektronski mikroskop, tankoslojni organski polprevodniki, P3HT, grafen, morfologija


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