Fabrication of micro-light-emitting diodes in nanoimprint lithography with diamond molds

研究了以聚甲基丙烯酸甲酯(PMMA)为印迹材料，采用化学气相沉积(CVD)金刚石模具，在纳米压印光刻(NIL)中制备微有机发光二极管(OLED)。采用电子束光刻技术，采用Bi4Ti3O&lt；L2&gt；辛酸(氧化物)掩模，制备了零工艺金刚石模具。研制了一种采用直流无心电机驱动的紧凑型印迹装置(宽28 cm、长15 cm、高25 cm)。结果表明，最佳压印条件为：压印压力0.8Mpa，压印时间15 mm，衬底温度180℃，去除温度70℃。用化学气相沉积法制备了间距为30μm和40μm的凹面方点金刚石模具。8-羟基喹啉铝(ALQ)、聚(9-乙烯基咔唑)(PVK)和香豆素-6分别作为电子传输材料、空穴传输材料和发射掺杂材料。采用压印技术制作的30μm方形点阵有机电致发光器件的结构为：氧化铟锡(ITO)、PVK(100 Nm)/Alq(50 Nm)/Al(100 Nm)。我们展示了微OLED器件的成功制造和运行。

Fabrication of micro-organic light emitting diodes (OLED) in nanoimprint lithography (NIL) with chemical vapor deposited (CVD) diamond molds using polymethyl methacrylate (PMMA) as an imprinting material was investigated. The diamond molds using NIL process were fabricated with Bi_4Ti_3O_<l2> octylate (oxide) mask in electron beam lithography technology. The compact imprint apparatus (28 cm in width, 15 cm in length and 25 cm in height) using the driving power of a direct current (DC) coreless motor was developed. It was found that the optimum imprint conditions are the following: imprinting pressure, press time, substrate temperature and removal temperature were 0.8 MPa 15 mm, 180℃ and 70℃ respectively. The resulting CVD diamond molds of a concave square dot with 30 μm and 40 μm pitch were fabricated. 8-Hydroxyquinoline-aluminum (Alq), Poly(9-vinylcalbazole) (PVK) and Coumarin-6 are used as electron transport, hole transport and an emitting dopant material, respectively. The device structure of 30 μm square dot OLED fabricated by imprinting technique is indium tin oxide (ITO)PVK(lOOnm)/Alq(5Onm)/Al(lOOnm). We demonstrated successful fabrication and operation of micro-OLED devices.