Ca2BO3Cl：Ce3＋, Ca2BO3Cl：Tb3＋, and Ca2BO3Cl：Ce3＋, Tb3＋ phosphors are synthesized by a high temperature solid-state reaction. The emission intensity of Ce3＋ or Tb3＋ in Ca2BO3Cl is influenced by the Ce3＋ or Tb3＋ doping content, and the optimum concentrations of Ce3＋ and Tb3＋ are 0.03 tool and 0.05 mol, respectively. The concentration quenching effect of Ce3＋ or Tb3＋ in Ca2BO3Cl occurs, and the concentration quenching mechanism is d-d interaction for either Ce3＋ or Tb3＋. The Ca21303Cl：Ce3＋, Tb3＋ can produce colour emission from blue to green by properly tuning the relative ratio between Ce3＋ and Tb3＋, and the emission intensity of Tb3＋ in Ca2BO3Cl can be enhanced by the energy transfer from Ce3＋ to Tb3＋. The results indicate that Ca2BO3Cl：Ce3＋, Tb3＋ may be a promising double emission phosphor for UV-based white light emitting diodes.
The contact effect on the performances of organic thin film transistors is studied here. A C60 ultrathin layer is inserted between Al source-drain electrode and pentacene to reduce the contact resistance. By a 3 nm C60 modification, the injection barrier is lowered and the contact resistance is reduced. Thus, the field-effect mobility increases from 0.12 to 0.52 cm2/（V.s）. It means that inserting a C60 ultra thin layer is a good method to improve the organic thin film transistor （OTFT） performance. The output curve is simulated by using a charge drift model. Considering the contact effect, the field effect mobility is improved to 1.15 cm2/（V-s）. It indicates that further reducing the contact resistance of OTFTs should be carried out.
