Interface Modification Of Organic Solar Cells Using Graphene Oxide Or Graphene Oxide Based Composite Materials

Graphene has received considerable attention for its excellent physical and chemical properties. Graphene Oxide?GO? and GO-based composites as the derivatives of graphene show excellent semiconductor properties after treatments,which make GO show a great potential in interface modification of organic solar cells?OSCs?. Traditional interface materials of OSCs, such as PEDOT:PSS[poly?styrenesul-fonate?/poly?3,4-ethylendioxythiophene?], usually have some problems such as hygroscopic properties, high acidity and inhomogeneous electrical properties, while GO is stable in the air atmosphere. Moreover, The thin GO film can contact well with the active layer of OSCs, that is P3HT?poly 3-hexylthiophene?:PCBM?[6,6]-phenylC61-butyric acid methyl ester?. In this work, we adopted a simple, practicable and environmentally friendly method to synthesize GO and GO composites, and apply them in the interface modification of OSCs.Details are summarized as follows:?1? Interface modification of OSCs using GO as hole transport layer?HTL? and TiO₂ NPs as electron transport layer?ETL?: in this work, we used improved methods to synthesize GO and TiO₂ NPs, Atomic Force Microscopy characterization is its main film characterization to analyze the film of OSCs. Moreover, the impedance spectra and Mott–Schottky study were used to analyze the interface performance of OSCs and applied the two materials in preparation of OSCs with the structure of ITO/GO/P3HT:PCBM/TiO₂ NPs/Al, which achieved comparable efficiency?3.37%?and a better stability?in high humidity atmospheric environment, degradation to 60%after 180 h? in contrast to traditional OSCs.?2? Interface modification of OSCs using the composite of reduced graphene oxide?RGO? and TiO₂ NPs as ETL: in this work, we used RGO preparation by the method of electrodeposition as the reference. Adopting the characterization such as AFM, SEM analyze the OSCs film performance, and through the chemical methods testing the film formation. Besides, a new hydrothermal process to synthesis RGO-TiO₂ NPs was studied. After a series of characterization and preparation of cell with the structure of ITO/PEDOT:PSS/P3HT:PCBM/RGO-TiO₂ NPs/Al, we proved its well photo-electricity performance with the power convert efficiency of 1.62%.?3? Application in perovskite solar cells using GO as HTL:In this work, we use GO as HTL in interface modification of perovskite solar cells, confirming GO canreplace traditional the material of HTL in perovskite solar cells, and prepared the efficient perovskite solar cells. To get the better perovskite film, here we utilized AFM characterization to test the information of perovskite film prepared by two different methods, and test its UV-Vis absorption performance which was match to the theory value. Applying GO in two different kinds of perovskite solar cells as HTL,and obtain the best power convert efficiency of 1.2%.