Abstract There are few techniques applicable to top-emitting organic light emitting diode (TOLED) panels, as organic films are easily deteriorated by heat stress, oxygen and moisture exposure when a light extraction structure is fabricated on top of TOLEDs. Recently, we have reported that a N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′diamine nano-lens array (NLA) fabricated by using a simple and highly process-compatible vacuum deposition works as an optically efficient structure when NLA with a lens size of several hundred nanometers is deposited on the oxide layer of the TOLED. To achieve the desirable optical properties of TOLEDs, the vacuum NLA process was controlled to obtain big nano-lenses with a diameter of several hundred nanometers, indicating the importance of understanding of the nucleation and growth behavior of NLA. Here, the systematic NLA experiments using glass and alumina substrates indicate that nano-lenses are formed by nucleation and growth of nuclei. Very interestingly, the nucleation is completed in the early stage of the deposition process, followed by growth without decreasing the total number of nano-lenses per area, and finally followed by growth with decreasing the total number due to Ostwald ripening. Compared to alumina substrates, smaller sizes and greater rates of nucleation of NLAs in glass substrates are explained by the difference in substrate surface energy combined with a classical thermodynamic theory using the difference in Gibbs free energy.

中文翻译：

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真空沉积制备的光学高效有机纳米透镜阵列的成核和生长

摘要 顶发光有机发光二极管（TOLED）面板技术很少，因为在TOLED上制作光提取结构时，有机薄膜容易受到热应力、氧气和湿气的影响而劣化。最近，我们报道了 N'-Di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'diamine 纳米透镜阵列 (NLA)当透镜尺寸为几百纳米的 NLA 沉积在 TOLED 的氧化物层上时，高度兼容的真空沉积可作为一种光学高效的结构。为了获得理想的 TOLED 光学特性，控制真空 NLA 工艺以获得直径为数百纳米的大纳米透镜，这表明了解 NLA 的成核和生长行为的重要性。这里，使用玻璃和氧化铝基板的系统 NLA 实验表明，纳米透镜是通过核的成核和生长形成的。非常有趣的是，成核是在沉积过程的早期阶段完成的，然后是生长而不减少每个区域的纳米透镜总数，最后是由于 Ostwald 成熟而减少总数的生长。与氧化铝基板相比，玻璃基板中 NLA 的更小尺寸和更高的成核率是由基板表面能的差异与使用吉布斯自由能差异的经典热力学理论相结合来解释的。成核在沉积过程的早期阶段完成，然后在不减少每个区域纳米透镜总数的情况下进行生长，最后随着 Ostwald 成熟而减少总数进行生长。与氧化铝基板相比，玻璃基板中 NLA 的更小尺寸和更高的成核率是由基板表面能的差异与使用吉布斯自由能差异的经典热力学理论相结合来解释的。成核在沉积过程的早期阶段完成，然后在不减少每个区域纳米透镜总数的情况下进行生长，最后随着 Ostwald 成熟而减少总数进行生长。与氧化铝基板相比，玻璃基板中 NLA 的更小尺寸和更高的成核率是由基板表面能的差异与使用吉布斯自由能差异的经典热力学理论相结合来解释的。