STUDY OF CATHODE INTERFACIAL LAYER FOR HIGHLY EFFICIENT INVERTED ORGANIC SOLAR CELLS

Abstract

Inverted organic solar cells (OSCs) have attracted much attention due to their approved stability and compatibility with roll-to-roll processes since their initial studies. The nature of electrical contact between the active layer and cathode in inverted OSCs has significant effects on the device performance, thus modification of those interfaces by inserting appreciate interfacial layers can optimize the contact properties to improve the device performance. The purpose of this work is to investigate the mechanism of the metal oxide interlayers and develop novel interfacial layer materials to modify the interface for highly efficient OSCs. In this thesis, three types of cathode interfacial layers, atomic layer deposited (ALD) and solution processed metal oxides (zinc oxide (ZnO) and titanium oxide (TiOx)), and polyelectrolyte (polyethyleneimine: poly(styrene sulfonate) sodium salt (PEI:PSS)), have been studied for inverted OSCs.