Deang Liu

High efficiency solution-processed thin-film Cu(In,Ga)(Se,S)2 solar cells

The polycrystalline chalcopyrite Cu(In,Ga)(Se,S)2 (CIGS) solar cell has been considered one of the most promising alternatives to conventional silicon solar cells, due to its achieving the highest power conversion efficiency (PCE) among all the thin-film photovoltaic technologies, potentially lowered production cost and compatibility with large area flexible substrates. Unfortunately, almost all the high efficiency CIGS devices are presently fabricated via vacuum-based techniques, which still require expensive facilities and high power consumption, thus leaving the fabrication cost issue unresolved. Herein, a hydrazine-based, solution processed CIGS device with high performance has been demonstrated through the construction of a composition grading profile of the CIGS absorber layer, which enhances the charge collection efficiency and maximizes the solar spectrum absorption. ZnO nanoparticles (ZnO NP), as the window layer, are proven to be an ideal alternative to sputtered ZnO, benefiting from high optical transparency, smooth and defectless interface, adjacent to the CIGS absorber layer. The CIGS solar cell with a certified PCE of 17.3% is achieved, which is the world record efficiency for solution-based CIGS solar cells, and also shortens the efficiency gap towards vacuum-based devices.

Photo-functional materials based on copper(I) complexes*

Abstract Copper(I) complexes are attractive photo-functional materials due to their rich photochemical and photophysical properties. It has been proved that these new materials have potential application in many fields, such as organic light-emitting diodes, optical sensor, nonlinear optics and dye sensitized solar cells. The goal of this review is to outline the progress in this field. Many aspects, including new ligands, stereochemical control and the construction of supramolecules, design of the excited states, the high-energy emission and low-energy emission, the Cu-Cu bonding interactions and applications, are discussed.