FRG: Study of Pi-Conjugated Organic Semiconductors with Tailored Spin-Orbit Coupling

技术。这个重点研究小组项目是有机材料科学与化学、光学、光电子学、磁输运和理论物理等专业研究人员的合作成果。智力优势：研究的目标是合成，电子和自旋现象的研究，以及新型p共轭半导体系统的光电/自旋电子学应用，该系统包括重原子（如铂）在其主结构中，以定制p电子激发的自旋轨道耦合。增加的自旋轨道（SO）耦合将增强单重态到三重态的系统间交叉，导致大的三重态产率。它还会产生相对于通常的光致发光（PL）波段红移的强磷光（PH）发射带。大的、定制的三重态产量将使高密度三重态的研究成为可能，包括它们的集体自旋相干性，从而可能对自旋量子比特进行量子操纵。该方法包括：(1)使用新的合成技术合成含Pt和Ir的p共轭体系，包括单体、聚合物和共聚物，并控制主链结构中重原子的数量。（ii）利用零场光学探测磁共振（ODMR）测量单重态和三重态激子的光学和自旋特性，包括ps时间分辨响应、PH和PL发射带的性质、电荷极化子的自旋随机化和三重态激子的自旋相干现象。（iii）通过PH- odmr中集体Rabi振荡的表现，研究高密度三重态的集体自旋相干性，当施加强共振微波辐射时，三重态通过相互超辐射相互作用耦合锁定在一起，也通过分析PH噪声谱。（iv）用铁磁自旋注入电极和重原子聚合物制备自旋有机发光二极管（S-OLED），用于研究在外加磁场作用下自旋定向载流子注入和输运时，电- pl和电- ph发射的相互作用。理论小组将通过向实验人员提供非常必要的反馈来支持研究活动；这包括了解高三重态密度下的集体拉比振荡，拉比振荡章动，PH发射噪声分析，以及三重态自旋亚能级内的磁声子共振。非技术。更广泛的影响：研究成果可能包括新的光电应用，如S-OLED和量子计算机的自旋量子位。此外，实验和理论的整合，包括聚合物合成，连续波和超快光学，磁输运，理论物理方法，以及器件制造，加工和测试，有望为研究生和本科生提供广泛的教育机会。

Technical. This focused research group project is a collaborative effort among researchers with expertise in Organic Materials Science and Chemistry, Optics, Optoelectronics, Magneto-transport and Theoretical Physics. Intellectual Merit: The goals of the research are the synthesis, study of electronic and spin phenomena, and optoelectronic/spintronics applications of novel p-conjugated semiconductor systems that include heavy atoms such as platinum in their backbone structure, in order to tailor the spin-orbit coupling of the p-electron excitations. The increased spin-orbit (SO) coupling would enhance the singlet to triplet intersystem crossing, leading to a large triplet yield. It would also result in a strong phosphorescence (PH) emission band that is red-shifted with respect to the usual photoluminescence (PL) band. The large, tailored triplet yield would enable the study of high-density triplets, including their collective spin coherence properties for possible quantum manipulation of spin-qubits. The approach includes: (i) synthesis of Pt- and Ir- containing p- conjugated systems including monomers, polymers and co-polymers using new synthesis techniques, with control over the number of the heavy atoms in the backbone structure. (ii) measurement of optical and spin properties of singlet and triplet excitons, including ps time resolved response, the nature of the PH and PL emission bands, spin randomization of charge polarons, and spin coherence phenomena of triplet excitons using zero-field optically detected magnetic resonance (ODMR). (iii) study of collective spin coherence properties of triplets at high density via the manifestation of collective Rabi oscillations in the PH-ODMR where triplets are locked together via their mutual superradiance interaction coupling when applying a strong, resonant microwave radiation, and also by analyzing the PH noise spectrum. (iv) fabrication of spin organic light emitting diodes (S-OLED) with ferromagnetic spin-injecting electrodes and heavy-atom polymers, for studying the interplay of electro-PL and electro-PH emissions upon application of an external magnetic field to spin aligned carrier injection and transport. The theory team will support the research activity by providing highly necessary feedback to the experimentalists; this includes understanding of collective Rabi oscillations at high triplet density, Rabi oscillations nutation, analysis of PH emission noise, and a magneto-phonon resonance within the triplet spin sublevels. Non-Technical. Broader Impact: Research outcomes may include novel optoelectronic applications such as S-OLED and spin qubits for quantum computers. In addition the integration of experimental and theoretical efforts, including polymer synthesis, cw and ultrafast optics, magneto-transport, theoretical physics methods, and device fabrication, processing and testing, is expected to provide broad educational opportunities for graduate and undergraduate students.