Patterning of Gd 2(WO 4) 3:Ln 3+ (Ln = Eu, Tb) luminescent films by microcontact printing route

Abstract

Gd 2(WO 4) 3 doped with Eu 3+ or Tb 3+ thin phosphor films with dot patterns have been prepared by a combinational method of sol–gel process and microcontact printing. This process utilizes a PDMS elastomeric mold as the stamp to create heterogeneous pattern on quartz substrates firstly and then combined with a Pechini-type sol–gel process to selectively deposit the luminescent phosphors on hydrophilic regions, in which a Gd 2(WO 4) 3:Ln 3+ (Ln = Eu, Tb) precursor solutions were employed as ink. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectra, as well as low voltage cathodoluminescence (CL) spectra were carried out to characterize the obtained samples. Under ultraviolet excitation and low-voltage electron beams excitation, the Gd 2(WO 4) 3:Eu 3+ samples exhibit a strong red emission arising from Eu 3+ 5D 0,1,2– 7F 1,2 transitions, while the Gd 2(WO 4) 3:Tb 3+ samples show the green emission coming from the characteristic emission of Tb 3+ corresponding to 5D 4– 7F 6,5,4,3 transitions. The results show that the patterning of rare earth-doped phosphors through combining microcontact printing with a Pechini-type sol–gel route has potential for field emission displays (FEDs) applications.