Hassan Tufail, Kim Jihyun, Manh Hung Ngo, Iqbal Aamir, Gao Zhenguo, Kim Hyerim, Hussain Noushad, Naqvi Shabbir Madad, Zaman Shakir, Narayanasamy Mugilan, Lee Sang Uck, Kang Joohoon, Koo Chong Min
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Republic of Korea.
School of Chemical Engineering, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Republic of Korea.
ACS Nano. 2024 Aug 27;18(34):23477-23488. doi: 10.1021/acsnano.4c06966. Epub 2024 Aug 12.
MXenes have garnered significant attention due to their atomically thin two-dimensional structure with metallic electronic properties. However, it has not yet been fully achieved to discover semiconducting MXenes to implement them into gate-tunable electronics such as field-effect transistors and phototransistors. Here, a semiconducting TiNT MXene synthesized by using a modified oxygen-assisted molten salt etching method under ambient conditions, is reported. The oxygen-rich synthesis environment significantly enhances the etching reaction rate and selectivity of Al from a TiAlN MAX phase, resulting in well-delaminated and highly crystalline TiNT MXene with minimal defects and high content of F and O, which led to its improved hydrophobicity and thermal stability. Notably, the synthesized TiNT MXene exhibited p-type semiconducting characteristics, including gate-tunable electrical conductivity, with a current on-off ratio of 5 × 10 and a hole mobility of ∼0.008 cm V s at 243 K. The semiconducting property crucial for thin-film transistor applications is evidently associated with the surface terminations and the partial substitution of oxygen in the nitrogen lattice, as corroborated by density functional theory (DFT) calculations. Furthermore, the synthesized TiNT exhibits strong light absorption characteristics and photocurrent generation. These findings highlight the delaminated TiNT as an emerging two-dimensional semiconducting material for potential electronic and optoelectronic applications.
MXenes因其具有原子级厚度的二维结构和金属电子特性而备受关注。然而，尚未完全实现发现半导体MXenes并将其应用于场效应晶体管和光电晶体管等栅极可调电子器件中。在此，报道了一种在环境条件下通过改进的氧辅助熔盐蚀刻法合成的半导体TiNT MXene。富氧的合成环境显著提高了从TiAlN MAX相蚀刻Al的反应速率和选择性，从而得到分层良好、结晶度高、缺陷最少且F和O含量高的TiNT MXene，这使其疏水性和热稳定性得到改善。值得注意的是，合成的TiNT MXene表现出p型半导体特性，包括栅极可调电导率，在243 K时电流开关比为5×10，空穴迁移率约为0.008 cm² V⁻¹ s⁻¹。密度泛函理论（DFT）计算证实，对于薄膜晶体管应用至关重要的半导体特性显然与表面终止和氮晶格中氧的部分取代有关。此外，合成的TiNT表现出强烈的光吸收特性和光电流产生。这些发现突出了分层的TiNT作为一种新兴的二维半导体材料在潜在电子和光电子应用中的潜力。
