Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, Utah 84112, USA.
Nat Mater. 2010 Apr;9(4):345-52. doi: 10.1038/nmat2633. Epub 2010 Feb 14.
Recent advances in organic spin response include long polaron spin-coherence times measured by optically detected magnetic resonance (ODMR), substantive room-temperature magnetoelectroluminescence and magnetoconductance obtained in organic light-emitting diodes (OLEDs) and spin-polarized carrier injection from ferromagnetic electrodes in organic spin valves (OSVs). Although the hyperfine interaction (HFI) has been foreseen to have an important role in organic spin response, no clear experimental evidence has been reported so far. Using the chemical versatility advantage of the organics, we studied and compared spin responses in films, OLED and OSV devices based on pi-conjugated polymers made of protonated, H-, and deuterated, D-hydrogen having a weaker HFI strength. We demonstrate that the HFI does indeed have a crucial role in all three spin responses. OLED films based on the D-polymers show substantially narrower magneto-electroluminescence and ODMR responses, and as a result of the longer spin diffusion obtained, OSV devices based on D-polymers show a substantially larger magnetoresistance.
有机自旋响应的最新进展包括通过光探测磁共振（ODMR）测量的长极化子自旋相干时间、在有机发光二极管（OLED）中获得的实质性室温电致发光和磁导率以及在有机自旋阀（OSV）中从铁磁电极注入的自旋极化载流子。尽管超精细相互作用（HFI）被预期在有机自旋响应中具有重要作用，但迄今为止尚未有明确的实验证据报道。利用有机物的化学多功能性优势，我们研究并比较了基于质子化、H-和氘化、HFI 强度较弱的 D-氢的π共轭聚合物的薄膜、OLED 和 OSV 器件中的自旋响应。我们证明 HFI 确实在所有三种自旋响应中都起着至关重要的作用。基于 D-聚合物的 OLED 薄膜显示出明显更窄的磁电致发光和 ODMR 响应，并且由于获得了更长的自旋扩散，基于 D-聚合物的 OSV 器件显示出更大的磁阻。
