RESUMEN
The passivation properties of a polysilicon (poly-Si) thin film are the key for improving the photovoltaic performance of TOPCon silicon solar cells. In this work, we investigate the influence of the poly-Si microstructure on the interface passivation and photovoltaic performance in TOPCon solar cells. The poly-Si thin films are prepared from phosphorus-doped hydrogenated microcrystalline silicon (µc-Si:H) layers deposited via plasma enhanced chemical vapor deposition (PECVD) under different hydrogen dilutions and recrystallized by high temperature post-deposition annealing. The results revealed that, as the hydrogen dilution ratio increases, the microstructure of the pre-deposited films transforms from an amorphous phase to a microcrystalline phase. Meanwhile, the effective minority carrier lifetime of the symmetrically passivated contact structure shows a maximum value of 1.75 ms, implying that the efficient passivation at the c-Si interface is obtained which is mainly attributed to the joint enhancement of the improved field effect passivation from poly-Si films and the reduced defects density on the silicon surface. Consequently, the devices displayed excellent rectification behavior with a rectifying ratio of 3 × 105, ascribed to the enhanced carrier transport with the high quality poly-Si film pre-deposited in the initial region of structural transition. Correspondingly, the obvious improvement of TOPCon solar cell performance was achieved, exhibiting an optimized conversion efficiency of 17.91%. The results provide an optimal design scheme for enhancing the photovoltaic properties of the TOPCon silicon solar cells.
RESUMEN
The organic passivated carbon nanotube (CNT)/silicon (Si) solar cell is a new type of low-cost, high-efficiency solar cell, with challenges concerning the stability of the organic layer used for passivation. In this work, the stability of the organic layer is studied with respect to the internal and external (humidity) water content and additionally long-term stability for low moisture environments. It is found that the organic passivated CNT/Si complex interface is not stable, despite both the organic passivation layer and CNTs being stable on their own and is due to the CNTs providing an additional path for water molecules to the interface. With the use of a simple encapsulation, a record power conversion efficiency of 22% is achieved and a stable photovoltaic performance is demonstrated. This work provides a new direction for the development of high-performance/low-cost photovoltaics in the future and will stimulate the use of nanotubes materials for solar cells applications.
RESUMEN
The nano-Ag films were prepared by RF magnetron sputtering technique, and all of them were treated by rapid thermal annealing at different temperatures. The structure, the morphology and the optical properties of the annealed nano-Ag films were characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis-NIR spectroscopy. The experimental results show that the open area fraction of the film and spacing between islands or nanoparticles increase with the increase of the annealing temperature, while the aspect ratio decreases. The anisotropic worm-like island films have been reshaped into isotropic nanospheres. The surface plasmon (SP) resonance band blue shifts and narrows continuously with increasing heating temperature. Analyses show that the SP resonance of the nano-Ag films can be modulated by morphology evolution induced by rapid thermal annealing.
RESUMEN
The title salt, [K(2)(C(16)H(12)O(6))](n), was obtained by the reaction of 1,2-bis-[4-(ethyl-carbox-yl)-phenox-yl]ethane with KOH in water. The anion lies on a crystallographic inversion center, which is located at the mid-point of the central C-C bond. The K(+) cation is coordinated by six O atoms, two from the chelating carboxyl-ate group of the anion and four from four neighboring and monodentately binding anions, giving rise to an irregular [KO(6)] coordination polyhedron. The coordination mode of the cation leads to the formation of K/O layers parallel to (100). These layers are linked by the nearly coplanar anions (r.m.s. deviation of 0.064â Å of the carboxyl, aryl and O-CH(2) groups from the least-squares plane) into a three-dimentional network.
