溶液法制备的硫氰酸亚铜（CuSCN）中空穴俘获态的起源及I$_2$掺杂的缺陷修复
Origin of Hole-Trapping States in Solution-Processed Copper(I) Thiocyanate (CuSCN) and Defect-Healing by I$_2$ Doping
AI总结：
本研究通过X射线吸收光谱揭示溶液法制备的CuSCN中SCN空位导致空穴俘获态，并提出I$_2$掺杂策略，以I$^-$替代缺失配体修复缺陷，使空穴迁移率提升五倍以上，并改善器件稳定性。
摘要：
溶液法制备的硫氰酸亚铜（CuSCN）通常表现出低结晶度和短程有序性；这些缺陷导致高密度的陷阱态，从而限制了器件性能。尽管CuSCN在电子领域应用广泛，但其缺陷性质尚未得到详细研究。通过X射线吸收光谱，发现由标准二乙基硫醚配方制备的原始CuSCN含有欠配位的Cu原子，表明存在SCN空位。我们提出了一种缺陷钝化策略，即在处理溶液中添加固态I$_2$。在低浓度下，碘以I$^-$形式存在，可替代缺失的SCN$^-$配体，有效修复缺陷位点并恢复Cu周围的配位。将I$_2$掺杂的CuSCN用作薄膜晶体管的p沟道，结果显示在最佳掺杂浓度0.5 mol%时，空穴迁移率提高了五倍以上。重要的是，开关电流比和亚阈值特性也得到改善，因为I$_2$掺杂方法实现了缺陷修复效果，同时避免了有害杂质态的产生。电容-电压特性分析证实，添加I$_2$后陷阱态密度降低。器件的接触电阻和偏压应力稳定性也有所改善。这项工作展示了一种简单有效的提高CuSCN空穴传输性能的途径，适用于广泛的电子和光电器件应用。
英文摘要：
Solution-processed copper(I) thiocyanate (CuSCN) typically exhibits low crystallinity with short-range order; the defects result in a high density of trap states that limit the device performance. Despite the extensive electronic applications of CuSCN, its defect properties have not been studied in detail. Through X-ray absorption spectroscopy, pristine CuSCN prepared from the standard diethyl sulfide-based recipe is found to contain under-coordinated Cu atoms, pointing to the presence of SCN vacancies. A defect passivation strategy is introduced by adding solid I$_2$ to the processing solution. At small concentrations, the iodine is found to exist as I$^-$ which can substitute for the missing SCN$^-$ ligand, effectively healing the defective sites and restoring the coordination around Cu. Applying I$_2$-doped CuSCN as a p-channel in thin-film transistors shows that the hole mobility increases by more than five times at the optimal doping concentration of 0.5 mol%. Importantly, the on/off current ratio and the subthreshold characteristics also improve as the I$_2$ doping method leads to the defect healing effect while avoiding the creation of detrimental impurity states. An analysis of the capacitance-voltage characteristics corroborates that the trap state density is reduced upon I$_2$ addition. The contact resistance and bias-stress stability of the devices also improve. This work shows a simple and effective route to improve hole transport properties of CuSCN which is applicable to wide-ranging electronic and optoelectronic applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
