Exploring the Triplet Spin Dynamics of the Charge-Transfer Co-crystal Phenazine/1,2,4,5-Tetracyanobenzene for Potential Use in Organic Maser Gain Media
Exploring the Triplet Spin Dynamics of the Charge-Transfer Co-crystal Phenazine/1,2,4,5-Tetracyanobenzene for Potential Use in Organic Maser Gain Media
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DOI：
10.1021/acs.jpcc.1c01654
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
Wern Ng;Shuyao Zhang;Hao Wu;Irena Nevjestić;Andrew J. P. White;M. Oxborrow
中科院分区：
文献类型：
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作者：
Wern Ng;Shuyao Zhang;Hao Wu;Irena Nevjestić;Andrew J. P. White;M. Oxborrow
电荷转移共晶体在有机电子和光伏领域的应用引起了人们的兴趣，在这些领域，它们易于通过溶液/气相沉积生长，并且在选择组成分子方面具有灵活性，从而可以定制它们的带隙和三重态自旋动力学。本文利用算法辅助连续波电子顺磁共振和x波段瞬态粉末电子顺磁共振（EPR）以及零场瞬态EPR （ZF-trEPR）研究了一类电荷转移共晶非那嗪/1,2,4,5-四氰苯（PNZ/TCNB）的三重态自旋动力学。零场分裂参数为|D| = 2118±2 MHz, |E| = 297±1 MHz，初始三重态亚能级种群Px/Py/ pz0 = 0.764:0.127:0.109。发现三重态自旋动力学的衰变时间在亚微秒范围内。此外，在aq增强介质腔的帮助下，PNZ/TCNB在445 nm脉冲激励下，可以在室温下输出2412 MHz的脉泽爆发和零场。这表明，如果提供一个具有足够高质量因子的腔，PNZ/TCNB是可行的，并为在室温和零场下研究其他具有类似三重态自旋动力学的电荷转移共晶体作为潜在脉泽增益介质开辟了途径。
Charge-transfer co-crystals have garnered interest for use in organic electronics and photovoltaics, where their ease of growth by solution/vapor deposition and flexibility in choice of constituent molecules allows tailoring of their band gaps and triplet spin dynamics. Here, we report on the triplet spin dynamics of one such charge-transfer co-crystal phenazine/1,2,4,5-tetracyanobenzene (PNZ/TCNB), as investigated using algorithm-assisted continuous-wave electron paramagnetic resonance and transient powder electron paramagnetic resonance (EPR) at X-band, as well as transient EPR at zero field (ZF-trEPR). The zero-field splitting parameters are |D| = 2118 ± 2 MHz and |E| = 297 ± 1 MHz, with initial triplet sublevel populations Px/Py/Pzbeing 0.764:0.127:0.109. The triplet spin dynamics were found to have decay times in the sub-microsecond regime. Furthermore, with the aid of aQ-boosted dielectric cavity, PNZ/TCNB can output a maser burst at 2412 MHz at room temperature and zero field under 445 nm pulsed excitation. This demonstrates that it is feasible for PNZ/TCNB to mase if a cavity with a sufficiently high-quality factor is provided and opens up avenues toward investigating other charge-transfer co-crystals with similar triplet spin dynamics as potential maser gain media at room temperature and zero field.