Buchholtz Stephanie A, Winkler L Conrad, Dorfner Maximilian F X, Kretschmer Fred, Kusber Anncharlott, Eymann Léonard Y M, Schmidt Theresa, Kleemann Hans, Benduhn Johannes, Ortmann Frank, Leo Karl
Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute of Applied Physics, Technische Universität Dresden, Nöthnitzer Straße 61, 01187, Dresden, Germany.
Department of Chemistry, TUM School of Natural Sciences, Technische Universität München, Lichtenbergstr. 4, 85748, Garching, Germany.
Adv Sci (Weinh). 2025 Apr;12(14):e2414959. doi: 10.1002/advs.202414959. Epub 2025 Feb 18.
High electrical conductivity and improved charge carrier injection enabled by molecular doping are pivotal for high-performance, energy-efficient, and stable organic optoelectronic devices. Molecular doping is a key element in device design and manufacturing of active-matrix organic light-emitting diode displays, a multi-billion dollar market. However, it is an inherent feature of state-of-the-art small molecule dopants and their charge-transfer complexes to strongly absorb in the visible and near-infrared spectral range. This parasitic effect results in absorption losses, reducing the performance in light-harvesting and light-emitting applications. Here, a novel class of vacuum-processable cerium-based p-dopants with excellent processing properties and competitive doping strength even in organic hole transport layers with low-lying valence levels is presented. A substantial reduction in parasitic absorption for layers doped by the new dopants in the visible and near-infrared range is found. The reduced polaron absorption of the dopant anions is in excellent agreement with theoretical simulations. By incorporating these dopants into near-infrared narrowband organic photodetectors, the specific detectivity can be increased by one order of magnitude compared to devices with the established dopant 1,3,4,5,7,8-hexafluorotetracyanonaphthoquinodimethane (F-TCNNQ). The decreased parasitic absorption yields optical-microcavity-enhanced photodetectors with significantly reduced full-width at half maximum, paving the way toward more efficient and wavelength-selective infrared detectors.
分子掺杂实现的高电导率和改善的电荷载流子注入对于高性能、节能且稳定的有机光电器件至关重要。分子掺杂是有源矩阵有机发光二极管显示器器件设计和制造中的关键要素，该显示器市场价值数十亿美元。然而，现有小分子掺杂剂及其电荷转移络合物的一个固有特性是在可见光和近红外光谱范围内有强烈吸收。这种寄生效应导致吸收损耗，降低了光捕获和发光应用中的性能。在此，提出了一类新型的可真空处理的铈基p型掺杂剂，其具有优异的加工性能，即使在价态较低的有机空穴传输层中也具有有竞争力的掺杂强度。发现用新掺杂剂掺杂的层在可见光和近红外范围内的寄生吸收大幅降低。掺杂剂阴离子的极化子吸收降低与理论模拟结果非常吻合。通过将这些掺杂剂纳入近红外窄带有机光电探测器，与使用已确立的掺杂剂1,3,4,5,7,8-六氟四氰基萘并二甲基苯醌（F-TCNNQ）的器件相比，比探测率可提高一个数量级。寄生吸收的降低产生了光学微腔增强的光电探测器，其半高宽显著减小，为更高效和波长选择性的红外探测器铺平了道路。
