High‐Density Integration of Ultrabright OLEDs on a Miniaturized Needle‐Shaped CMOS Backplane
High‐Density Integration of Ultrabright OLEDs on a Miniaturized Needle‐Shaped CMOS Backplane
复制标题
在微型针形 CMOS 背板上高密度集成超亮 OLED
DOI：
10.1002/adma.202300578
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发表时间：
2023
影响因子：
29.4
通讯作者：
Gather, Malte C.
中科院分区：
文献类型：
--
作者：
Hillebrandt, Sabina;Moon, Chang‐Ki;Taal, Adriaan J.;Overhauser, Henry;Shepard, Kenneth L.;Gather, Malte C.
在硅基互补金属氧化物半导体（CMOS）芯片上直接沉积有机发光二极管（OLED）已经实现了具有高分辨率和填充因子的自发射微显示器。OLED在增强和虚拟现实（AR/VR）显示器和生物医学应用中的新兴应用，例如，作为用于光遗传学中细胞特异性光递送的脑植入物，需要比传统显示器中发现的光强度高几个数量级的光强度。进一步的要求通常包括微观器件覆盖区、特定形状和超稳定钝化，例如，以确保OLED植入物的生物相容性和微创性。在这项工作中，多达1024个超亮，显微OLED直接沉积在针形CMOS芯片上。对CMOS芯片的代工厂提供的铝接触焊盘进行透射电子显微镜和能量色散X射线光谱分析，以指导接触的系统优化。等离子体处理和银夹层的实施导致欧姆接触条件，从而促进橙子和蓝色发光OLED叠层的直接真空沉积，导致芯片上的微米尺寸像素。每个针中的电子器件允许每个像素单独切换。OLED像素产生的平均光功率密度为0.25 mW mm−2，相当于>40 000 cd m−2，远高于日光AR应用和大脑中光遗传单单位激活的要求。
Direct deposition of organic light‐emitting diodes (OLEDs) on silicon‐based complementary metal–oxide–semiconductor (CMOS) chips has enabled self‐emissive microdisplays with high resolution and fill‐factor. Emerging applications of OLEDs in augmented and virtual reality (AR/VR) displays and in biomedical applications, e.g., as brain implants for cell‐specific light delivery in optogenetics, require light intensities orders of magnitude above those found in traditional displays. Further requirements often include a microscopic device footprint, a specific shape and ultrastable passivation, e.g., to ensure biocompatibility and minimal invasiveness of OLED‐based implants. In this work, up to 1024 ultrabright, microscopic OLEDs are deposited directly on needle‐shaped CMOS chips. Transmission electron microscopy and energy‐dispersive X‐ray spectroscopy are performed on the foundry‐provided aluminum contact pads of the CMOS chips to guide a systematic optimization of the contacts. Plasma treatment and implementation of silver interlayers lead to ohmic contact conditions and thus facilitate direct vacuum deposition of orange‐ and blue‐emitting OLED stacks leading to micrometer‐sized pixels on the chips. The electronics in each needle allow each pixel to switch individually. The OLED pixels generate a mean optical power density of 0.25 mW mm−2, corresponding to >40 000 cd m−2, well above the requirement for daylight AR applications and optogenetic single‐unit activation in the brain.