硅衬底上聚丙烯酰胺/氧化锌纳米线薄膜蓝色发光二极管

BLUE LIGHT-EMITTING DIODE BASED ON ZnO NANOWIRE/POLYACRYLAMIDE FILM ON SILICON SUBSTRATE

采用高分子络合软模板法利用高分子络合和低温氧化烧结反应,在硅衬底上自组装生长出顶面平滑具有六角柱形结构的ZnO纳米线,并基于此聚丙烯酰胺/ZnO纳米线体系构筑了聚合物基ZnO纳米线发光二极管器件,在相对低的阈值电压下实现了常温常压下电场驱动的蓝色发射光,并且其发光颜色可由其应用的激励电压方便地调控.几乎垂直排列的ZnO纳米线/高分子薄膜在器件中被作为发射层.该方法使用聚合物作为LED器件的粘结剂和发光层的分散介质,稳定了硅衬底上埋置在聚合物薄膜中的ZnO纳米线准阵列并对ZnO纳米晶的表面起钝化作用,防止发光猝灭.结果表明,新技术是一种低成本制备ZnO基紫外/蓝色发光材料的工艺,并且减少了以往工艺中要求ZnO薄膜p型掺杂的麻烦.

The single crystalline ZnO nanowires were self-assembly grown on n-type （111） plane of the silicon substrate using polymer assisted complexing soft-template process through a simple polymer complexation and lowtemperature oxidizing-sintering, which have smooth top and fine hexagonal columnar structure. Based on the ZnO nanowire/polyacrylamide system, we construct the ZnO-nanowire/polyacrylamide light emitting device that exhibits blue electrically driven emission with a relatively low threshold voltage at ambient temperature and pressure, and the ZnO-nanowire-based LED＇s emission wavelength is easily tuned by controlling the applied excitation voltage. The nearly vertically aligned ZnO-nanowires with polyacrylamide film were used as emissive layers in the devices. The method uses polyacrylamide as binder in the LED device and dispersion medium in the luminescence layer, which stabilizes the quasi-arrays of ZnO nanowires embedding in a thin polyacrylamide film on silicon substrate and passivates the surface of ZnO nanocrystals, to prevent the quenching of luminescence. The results indicated that the novel technique is a low-cost process for ZnO-based UV or blue light emission and reduces the requirement for achieving robust p-doping of ZnO film. It suggests that such ZnO-nanowire/polyacrylamide-based LEDs will be promising for use in flat-panel displays.