High-efficiency cascade CdS/CdSe quantum dot-sensitized solar cells based on hierarchical tetrapod-like ZnO nanoparticles

Quantum dot-sensitized solar cells (QDSCs) constructed using cascade CdS/CdSe sensitizers and the novel tetrapod-like ZnO nanoparticles have been fabricated. The cascade co-sensitized QDSCs manifested good electron transfer dynamics and overall power conversion efficiency, compared to single CdS- or CdSe-sensitized cells. The preliminary CdS layer is not only energetically favorable to electron transfer but behaves as a passivation layer to diminish the formation of interfacial defects during CdSe synthesis. On the other hand, the anisotropic tetrapod-like ZnO nanoparticles, with a high electron diffusion coefficient, can afford a better carrier transport than traditional ZnO nanoparticles. The resultant solar cell yielded an excellent performance with a solar power conversion efficiency of 4.24% under simulated one sun (AM1.5G, 100 mW cm(-2)) illumination.     

Determination of Plasma Density Profile and Other Parameters of Cylindrical Plasma Columns with an Electroacoustic Probe

A new diagnostic method based on the excitation of thermal resonances using an electroacoustic probe has been developed to determine the electron density profile and other plasma parameters of a cylindrical warm-plasma column. A coaxial electroacoustic probe is used to excite and detect the dipole and thermal resonances as the plasma density is varied. The electron density profile is expressed functionally in terms of unknown profile parameters. The profile and other parameters of the plasma column are then determined numerically based on some theoretical formulas and experimental results.