TWO DIMENSIONAL MATERIALS MADE FROM ORGANIC AND INORGANIC HYBRIDS

Abstract

This thesis concerns the solution phase synthesis of inorganic and organic hybrid materials, followed by detailed characterization to understand the electrically driven charge storage or photochemical charge conversion properties of these materials. For the first part of my thesis, I will describe the intercalation of bulk TMD crystals with alkali metal to form quasi-2D intercalated ternary compounds (for example, LiXMoS2) for energy storage. Then I will discuss the interesting properties of Ruddlesden-Popper layered perovskites (RPPs) single crystals of n = 1 to 4 homologous series of (C4H9NH3)2(CH3NH3)Pb2I7. Bulk RPPs crystals were exfoliated to give molecularly thin layers, from which the photo-physical properties were studied and compared with bulk crystal. The surface relaxation in these ultrathin crystals was tracked in-situ using atomically resolved scanning probe microscopy. Photodetectors fabricated on these ultrathin flakes yielded very high photoresponsivity and photogain. Finally, field effect transistors were also fabricated on these ultrathin perovskites in order to study the transport properties. We found that ultrathin 2D perovskites were readily deformed by interfacial strains and their energy landscapes could be modified much more readily than the bulk crystals, making them good candidates for strain-engineered devices.