低温原子层沉积封装技术在OLED上的应用及对有机、钙钛矿太阳能电池封装的启示

Application of Low Temperature Atomic Layer Deposition Packaging Technology in OLED and Its Implications for Organic and Perovskite Solar Cell Packaging

有机半导体光电器件在基础研究和工业应用方面进展迅速,相关方向已经成为一个较为成熟的新兴领域.然而,这类器件中的关键有机材料存在对空气中的水、氧十分敏感的问题,严重影响了器件的长期工作性能.除了选择合适的传输层材料、界面层结构,利用界面工程提高器件水氧耐受能力之外,对器件进行可靠的封装是隔绝空气中水、氧的另一个有效手段.原子层沉积(atomiclayerdeposition,ALD)是一种近乎完美的薄膜沉积封装技术,这种技术所生长的薄膜具有独特的层-层(layer by layer)生长特性,而且可以在低温下沉积出厚度可控、重复率高、均匀致密的薄膜,使得该技术在半导体行业已经得到广泛应用.在此,我们将回顾ALD封装技术在有机发光二极管(organiclightemitting diode, OLED)、有机太阳能电池(organic photovoltaics, OPV)和钙钛矿太阳能电池(perovskite solar cell, PSC)中的应用,并进一步讨论现阶段应用于OLED的相对比较成熟的ALD封装技术,及其对OPV和PSC封装的启示性意义.

Organic semiconductor optoelectronic devices have made rapid development and progress in both research and industrial applications. The related directions have become a mature and emerging field. However, the organic materials in such devices usually are extremely sensitive to water vapor or oxygen existed in ambient air, which seriously affects the long-term stability of the devices. In addition to interface engineering, selecting appropriate charge(holes or electrons)transport layers and interfacial materials to improve the water and oxygen tolerance of the device and packing the device with robust encapsulation are all effective strategies to isolate the device from the water and oxygen in ambient air. Among various encapsulation technologies, atomic layer deposition(ALD) is an almost perfect encapsulation approach, which could deposit thin films in the layer-by-layer growth mode at low-temperature, with the characteristics of accurate and controllable thickness, high repeatability, excellent uniformity and high density. These characteristics make ALD to be widely used in semiconductor industry. Here, we review the progress of the applications of the ALD encapsulation techniques in organic light emitting diode(OLED) and provide further discussions on the enlightening significance of ALD encapsulation techniques in organic photovoltaics(OPV) and perovskite solar cell(PSC) encapsulations.