The role of oxygen in dramatically enhancing the electrical properties of solution-processed Zn-Sn-O thin-film transistors
The role of oxygen in dramatically enhancing the electrical properties of solution-processed Zn-Sn-O thin-film transistors
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DOI：
10.1039/c7tc01190c
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发表时间：
2017-07
影响因子：
6.4
通讯作者：
Soyeon Cho;Jong-Heon Yang;Jong Gyu Oh;S. Cho;Chi-Sun Hwang;Jaeyoung Jang;Sooji Nam
中科院分区：
文献类型：
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作者：
Soyeon Cho;Jong-Heon Yang;Jong Gyu Oh;S. Cho;Chi-Sun Hwang;Jaeyoung Jang;Sooji Nam
在溶液处理的金属氧化物半导体中形成金属-氧化物-金属（M-O-M）键的机制可以根据所使用的前体的类型而变化。迄今为止，主要研究了金属醇盐或金属氯化物前体;因此，改善氧化物薄膜晶体管（TFT）的器件特性的努力限于这些类型的前体。另一方面，系统的研究，以优化实验条件（如厚度和退火气氛）的氧化物TFT通过使用新类型的前体很少有报道。在这项研究中，我们成功地证明了高性能的解决方案处理的Zn-Sn-O TFT通过使用金属羧酸盐前体，锡（II）2-乙基己酸，并优化氧化物厚度和热退火条件。为了确定Zn-Sn-O的最佳厚度，我们制备了3种不同厚度的ZnO和SnO 2组合的有源层。此外，我们发现，氧气在退火过程中最大限度地形成的M-O-M键，并减少了陷阱的数量在厚度优化的有源层，导致显着增强的器件性能。结果，基于2-乙基己酸锡（II）的优化的Zn-Sn-O TFT表现出超过22 cm 2 V-1 s-1的优异迁移率，这比先前报道的基于相同前体的Zn-Sn-O TFT高一个数量级，并且与从常规溶液处理的金属氧化物TFT获得的迁移率水平非常相似。我们相信，我们的方法将丰富目前的锡前体家族，并为资源友好，低成本和高性能的Zn-Sn-O半导体提供另一种选择。
The mechanism of formation of metal–oxide–metal (M–O–M) bonds in solution-processed metal oxide semiconductors can vary depending on the types of precursors used. To date, metal-alkoxides or metal-chloride precursors have mainly been studied; therefore, efforts to improve the device characteristics of oxide thin-film transistors (TFTs) have been limited to these types of precursors. On the other hand, systematic studies to optimize the experimental conditions (e.g. thickness and annealing atmosphere) of oxide TFTs made by using new types of precursors have rarely been reported. In this study, we successfully demonstrate high-performance solution-processed Zn–Sn–O TFTs by using a metal-carboxylate precursor, tin(II) 2-ethylhexanoate, and optimizing the oxide thickness and thermal annealing conditions. To determine the optimum thickness of Zn–Sn–O, we prepared 3 types of active layers with different thickness combinations of ZnO and SnO2. In addition, we found that oxygen gas in the annealing process maximizes the formation of M–O–M bonds and decreases the number of trap sites in the thickness-optimized active layer, leading to dramatically enhanced device performances. As a result, the optimized Zn–Sn–O TFTs based on tin(II) 2-ethylhexanoate exhibit excellent mobility exceeding 22 cm2 V−1 s−1, which is an order of magnitude higher than that of the previously reported Zn–Sn–O TFTs based on the same precursor and very comparable to the mobility levels obtained from conventional solution-processed metal-oxide TFTs. We believe that our approach will enrich the current family of tin precursors and provide another option for resource-friendly, low-cost, and high performance Zn–Sn–O semiconductors.