Printable organic Electrochromic (EC) materials have gained increasing attention with respect to other chromogenic materials. A wide range of possible applications is rising thanks to their combination with other printable technologies such as Printable and Molecular Electronics (PME) and Organic Photovoltaic cells (OPV). The present work starts from the exploration of the properties of a new kind of PEDOT, one of the most studied electrochromic materials, developed in Università Bicocca of Milan. This PEDOT is soluble in nitromethane. Once the properties of the single film of PEDOT are analysed, a symmetrical EC device (ECD) is presented and characterized. The dependences of these properties on main device parameters such as thicknesses of active layers and electrolytic gel layer are evaluated. The experimental results presented in the first part are used in the second one to develop Quality Management (QM) of sunglasses exploiting electrochromic technology, followed by a brief discussion of two possible Supply Chain (SC) solutions for this new product. The behaviour of the studied ECD absorbance versus applied voltage have been demonstrated to be symmetric and directly proportional in the range (0, ±1,2V), along with the dependence of absorbance levels on PEDOT layers’ thickness. Electrochromic contrast depends then on PEDOT layers’ thickness as well. Optical Memory and Switching Speed have been demonstrated to depend strongly on gel layer thickness. In particular, even for the highest gel layer thickness considered, switching time is as low as few seconds for a 1cm2 wide device. Write-Erase efficiency is 100% and absorbance Stability up to 17000 cycles have been shown. The colouring efficiency have been shown to not depend neither on PEDOT nor gel layer thickness, but strongly on manufacturing quality of the device. In a first approximation, this ECD can be modelled as a capacitor. The good properties of this ECD, in particular switching speed and controllability with applied voltage or current, made this device particularly suitable for eye protection applications, especially sunglasses. Tools of Quality Management have been applied to Electrochromic Sunglasses, showing that they can bring the maximum benefit to customers looking for sunglasses for driving. Two possible models of Supply Chain have been proposed, with a focal company selling either directly the EC sunglasses or providing EC lenses to other sunglasses companies, adopting the marketing strategy called “Ingredient Branding”.
I materiali Elettrocromici (EC) organici stampabili hanno guadagnato una maggiore attenzione sugli altri materiali cromogeni grazie alla varietà di possibili applicazioni derivanti dalla loro combinazione con altre tecnologie stampabili quali l’Elettronica Stampabile e Molecolare (PME) e le celle Fotovoltaiche Organiche (OPV). Il presente lavoro parte da un nuovo tipo di PEDOT, solubile in nitrometano, sintetizzato nei laboratori dell’Università Bicocca di Milano. Una volta analizzate le proprietà del singolo film di PEDOT, viene presentato un Dispositivo Elettrocromico (ECD) simmetrico, caratterizzato poi utilizzando i parametri standard per gli ECD che si trovano in letteratura. È poi valutata la dipendenza di tali parametri dallo spessore degli strati di PEDOT e di gel elettrolitico. I risultati sperimentali della prima parte di lavoro sono utilizzati nella seconda per sviluppare il Quality Management (QM) di occhiali da sole che sfruttano gli ECD, seguito da una breve discussione su due possibili modelli di Supply Chain (SC) per questo nuovo prodotto. La dipendenza dell’assorbanza in funzione della tensione applicata dell’ECD in questione si è dimostrata essere simmetrica e direttamente proporzionale nella finestra (0, ±1,2V), in aggiunta a una dipendenza dell’assorbanza stessa dallo spessore degli strati di PEDOT, allo stesso modo del Contrasto Elettrocromico. La Memoria Ottica e la Velocita di Switching dipendono fortemente dallo spessore dello strato di gel. In particolare, il tempo necessario per transire di un ECD da 1cm2 è di pochi secondi anche per lo spessore di gel maggiore considerato. La Write-Erase Efficiency è del 100% e la Stabilità dell’assorbanza è stata dimostrata fino a 17000 cicli. L’efficienza di colorazione si è dimostrato non dipendere tanto dallo spessore dei diversi strati quanto dalla qualità manifatturiera del dispositivo stesso. In prima approssimazione, l’ECD è modellizzato come un capacitore. Le buone proprietà dell’ECD, in particolare la velocità di transizione e la controllabilità tramite tensioni o correnti applicate, rende tale dispositivo adeguato per applicazioni per la protezione dell’occhio, in particolare occhiali da sole. Strumenti del QM sono stati applicati agli occhiali da sole elettrocromici, mostrando che possono portare il massimo beneficio a utenti che cercano occhiali da sole per la guida. Due modelli di SC sono stati proposti, uno dove l’azienda di interesse vende direttamente gli occhiali EC, l’altro dove vende lenti EC ad altre aziende, con la strategia di mercato dell’“Ingredient Branding”.
Study and characterization of electrochromic device. A relevant application : sunglasses
LANFRANCHI, DAVIDE
2016/2017
Abstract
Printable organic Electrochromic (EC) materials have gained increasing attention with respect to other chromogenic materials. A wide range of possible applications is rising thanks to their combination with other printable technologies such as Printable and Molecular Electronics (PME) and Organic Photovoltaic cells (OPV). The present work starts from the exploration of the properties of a new kind of PEDOT, one of the most studied electrochromic materials, developed in Università Bicocca of Milan. This PEDOT is soluble in nitromethane. Once the properties of the single film of PEDOT are analysed, a symmetrical EC device (ECD) is presented and characterized. The dependences of these properties on main device parameters such as thicknesses of active layers and electrolytic gel layer are evaluated. The experimental results presented in the first part are used in the second one to develop Quality Management (QM) of sunglasses exploiting electrochromic technology, followed by a brief discussion of two possible Supply Chain (SC) solutions for this new product. The behaviour of the studied ECD absorbance versus applied voltage have been demonstrated to be symmetric and directly proportional in the range (0, ±1,2V), along with the dependence of absorbance levels on PEDOT layers’ thickness. Electrochromic contrast depends then on PEDOT layers’ thickness as well. Optical Memory and Switching Speed have been demonstrated to depend strongly on gel layer thickness. In particular, even for the highest gel layer thickness considered, switching time is as low as few seconds for a 1cm2 wide device. Write-Erase efficiency is 100% and absorbance Stability up to 17000 cycles have been shown. The colouring efficiency have been shown to not depend neither on PEDOT nor gel layer thickness, but strongly on manufacturing quality of the device. In a first approximation, this ECD can be modelled as a capacitor. The good properties of this ECD, in particular switching speed and controllability with applied voltage or current, made this device particularly suitable for eye protection applications, especially sunglasses. Tools of Quality Management have been applied to Electrochromic Sunglasses, showing that they can bring the maximum benefit to customers looking for sunglasses for driving. Two possible models of Supply Chain have been proposed, with a focal company selling either directly the EC sunglasses or providing EC lenses to other sunglasses companies, adopting the marketing strategy called “Ingredient Branding”.File | Dimensione | Formato | |
---|---|---|---|
2018_4_Lanfranchi.pdf
accessibile in internet solo dagli utenti autorizzati
Descrizione: Testo della tesi
Dimensione
5.53 MB
Formato
Adobe PDF
|
5.53 MB | Adobe PDF | Visualizza/Apri |
I documenti in POLITesi sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/10589/139080