The interface between graphene and organic layers is a key factor responsible for the performance of graphene-based organic solar cells(OSCs). In this paper, we focus on coating PEDOT:PSS onto the surface of graphene. We demonstrate two approaches, applying UV/Ozone treatment on graphene and modifying PEDOT:PSS with Zonyl, to get a PEDOT:PSS well-coated graphene film. Our results prove that both methods can be effective to solve the interface issue between graphene and PEDOT: PSS. Thereby it shows a positive application of the composited graphene/PEDOT:PSS film on graphene-based OSCs.
Heterojunction and sandwich architectures are two new-type structures with great potential for solar cells.Specifically,the heterojunction structure possesses the advantages of efficient charge separation but suffers from band offset and large interface recombination;the sandwich configuration is favorable for transferring carriers but requires complex fabrication process.Here,we have designed two thin-film polycrystalline solar cells with novel structures:sandwich CIGS and heterojunction perovskite,referring to the advantages of the architectures of sandwich perovskite(standard)and heterojunction CIGS(standard)solar cells,respectively.A reliable simulation software wxAMPS is used to investigate their inherent characteristics with variation of the thickness and doping density of absorber layer.The results reveal that sandwich CIGS solar cell is able to exhibit an optimized efficiency of 20.7%,which is much higher than the standard heterojunction CIGS structure(18.48%).The heterojunction perovskite solar cell can be more efficient employing thick and doped perovskite films(16.9%)than these typically utilizing thin and weak-doping/intrinsic perovskite films(9.6%).This concept of structure modulation proves to be useful and can be applicable for other solar cells.
Tianyue WangJiewei ChenGaoxiang WuDandan SongMeicheng Li
The crack propagation and domain switching process around the indentation on the surface of barium titanate single crystal under the external electric field was investigated by atomic force microscope and polarized light microscope.The evolutions of domain switching and crack propagation were in-situ observed when a 90 a c domain wall moved across the indentation which was driven by external electric field.The results show that the incompatible strain induced by domain switching in the residual stress zone around the indentation is the driving force of the anisotropic crack propagation.The crack propagation results in the changes of the fine domain stripes around the crack tip.
