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

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 fihns 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.