Lee Won Hyung, Yoon Sun Geun, Jin Huding, Yoo Jeeyoung, Han Junghyup, Cho Yong Hyun, Kim Youn Sang
Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, 08826, Republic of Korea.
School of Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
Adv Mater. 2021 Mar;33(10):e2007581. doi: 10.1002/adma.202007581. Epub 2021 Feb 4.
The change in electrical properties of electrodes by adsorption or desorption at interfaces is a well-known phenomenon required for signal production in electrically transduced sensing technologies. Furthermore, in terms of electrolyte-insulator-semiconductor (EIS) structure, several studies of energy conversion techniques focused on ion-adsorption at the solid-liquid interface have suggested that the electric signal is generated by ionovoltaic phenomena. However, finding substantial clues for the ion-adsorption phenomena in the EIS structure is still a difficult task because direct evidence for carrier accumulation in semiconductors by Coulomb interactions is insufficient. Here, a sophisticated Hall measurement system is demonstrated to quantitatively analyze accumulated electron density-change inside the semiconductor depending on the ion-adsorption at the solid-liquid interface. Also, an enhanced EIS-structured device is designed in an aqueous-soaked system that works with the ionovoltaic principle to monitor the ion-dynamics in liquid electrolyte media, interestingly confirming ion-concentration dependence and ion-specificity by generated peak voltages. This newly introduced peculiar method contributes to an in-depth understanding of the ionovoltaic phenomena in terms of carrier actions in the semiconductors and ionic behaviors in the aqueous-bulk phases, providing informative analysis about interfacial adsorptions that can expand the scope of ion-sensing platforms.
电极在界面处通过吸附或解吸引起的电学性质变化是电传感技术中信号产生所需的一种众所周知的现象。此外，就电解质-绝缘体-半导体（EIS）结构而言，一些专注于固液界面离子吸附的能量转换技术研究表明，电信号是由离子光伏现象产生的。然而，由于通过库仑相互作用在半导体中载流子积累的直接证据不足，在EIS结构中寻找离子吸附现象的实质性线索仍然是一项艰巨的任务。在此，展示了一种精密的霍尔测量系统，用于定量分析取决于固液界面离子吸附的半导体内部积累电子密度的变化。此外，在水浸系统中设计了一种增强型EIS结构的器件，该器件基于离子光伏原理工作，以监测液体电解质介质中的离子动力学，有趣的是通过产生的峰值电压证实了离子浓度依赖性和离子特异性。这种新引入的独特方法有助于从半导体中的载流子行为和水相中的离子行为方面深入理解离子光伏现象，提供有关界面吸附的信息分析，从而可以扩展离子传感平台的范围。
