Patterning of Gd2(WO4)3:Ln3+ (Ln = Eu, Tb) luminescent films by microcontact printing route

Gd2(WO4)3 doped with Eu3+ or Tb3+ 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 Gd2(WO4)3:Ln3+ (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 Gd2(WO4)3:Eu3+ samples exhibit a strong red emission arising from Eu3+5D0,1,2–7F1,2 transitions, while the Gd2(WO4)3:Tb3+ samples show the green emission coming from the characteristic emission of Tb3+ corresponding to 5D4–7F6,5,4,3 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.

Fluorescence microscope images of the patterned films for Gd2(WO4)3:Eu3+ (a) and Gd2(WO4)3:Tb3+ (b) under 254 nm UV irradiation.Figure optionsDownload high-quality image (20 K)Download as PowerPoint slideHighlights
► The patterned luminescent Gd2(WO4)3:Ln3+ (Ln = Eu, Tb) films were prepared via microcontact printing.
► The Pechini-type sol–gel method was combined with softlithography.
► They show luminescence under ultraviolet and low-voltage electron beams excitation.
► This technique has potential for field emission displays (FEDs) applications.