Search

Besides the widely investigated potential as alternative to silicon in microelectronics, semiconducting 2D transition metal dichalcogenides (TMDs) also show appealing prospects in thin film transistors (TFTs)‐based applications, while still suffer from insufficient demonstration. Herein, the authors systematically report high‐performance and low‐power chemical vapor deposition‐grown polycrystalline molybdenum ditelluride (MoTe2) TFTs with solution‐processed ternary Hf0.5Zr0.5O2/HfAlO2 high‐k dielectric. Benefitting from the optimized high quality HfAlO2 film synthesis and proper postannealing treatment, the constructed MoTe2 TFTs exhibit a high mobility ≈27.24 cm2 V−1 S−1, a current on/off ratio ≈6.43 × 105, threshold voltage ≈−3.27 V, and subthreshold swing (SS) value ≈152.4 mV dec−1, respectively. Moreover, by supplementing another solution‐processed layer of ferroelectric Hf0.5Zr0.5O2 to form double layer of HfAlO2/Hf0.5Zr0.5O2 dielectric, the device performance can be further improved with an ignorable hysteresis, increased mobility of ≈55.53 cm2 V−1 S−1, and significantly reduced SS value of ≈110.16 mV dec−1, respectively. The current investigation offers a feasible strategy to fabricate high‐performance and low‐power MoTe2 TFTs for potential TMDs‐based TFTs applications. [ABSTRACT FROM AUTHOR]

2D transition metal dichalcogenides (TMDs) have emerged as an ideal alternative to silicon in advanced electronics. Especially, MoTe2 attracts peculiar attention since it offers a unique opportunity of resolving critical electrical contacts. Currently, although MoTe2‐based coplanar semiconductor‐metal circuitry realized by epitaxial growth and chemical assembly has been demonstrated, while still suffers from the requirement of extremely accurate synthesis process control. Here, a facile strategy is demonstrated to fabricate large scale and high performance MoTe2 transistors with a 1T'/2H vertical homojunction structure by combining a spatial and phase controlled MoTe2 scalable synthesis and a scalable universal transfer method with water‐soluble poly‐vinylpyrrolidone and poly‐(vinyl alcohol) bilayer mediator. Both high quality 1T'‐ and 2H‐ MoTe2 with controlled dimensions can be scalable synthesized via a shadow mask assisted chemical vapor deposition method. These as‐synthesized MoTe2 patterns can be successfully transferred to a wide range of substrates at a high yield >80% with well‐retained properties to construct transistors with a complex vertical 1T'/2H‐MoTe2/HfAlO2 structure. The devices exhibit an on/off current ratio surpassing 104 and a typical mobility of ≈29 cm2 V−1 s−1. The developed scaled strategy of combining both scalable MoTe2 synthesis and transfer offers a feasible way for potential MoTe2‐based large‐scale electronics. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) based on planar SnO2 (p‐SnO2) demonstrate excellent performance due to the superior properties of SnO2 as electron transporting layer (ETL). However, at present mesoporous SnO2 (m‐SnO2) still lags behind p‐SnO2 due to problems in the fabrication process of m‐SnO2. In this paper, a new strategy for preparing m‐SnO2 ETL is introduced which owns two valuable features: First, it applies a low temperature process to make mesoporous structure, which favors preserving the pristine properties of the raw SnO2 nanocrystals. Second, the degree of porosity and roughness of the m‐SnO2 layer can be well controlled, making it friendly to the following deposition process of PSCs. The performance of the PSCs based on the m‐SnO2 ETL prepared from this strategy shows an obvious improvement which is mainly from the improvement in Jsc and FF, suggesting a higher carrier collection efficiency for the m‐SnO2 ETL. The relevant characterizations including PL, TRPL, EIS, and KPFM confirm that the m‐SnO2 ETL possesses stronger electron extraction capability than the p‐SnO2 ETL. Hence, the proposed strategy can manifest the advantages of m‐SnO2 ETL meanwhile refrain its negative impacts, and thus promote the progress of the m‐SnO2 ETL‐based PSCs. [ABSTRACT FROM AUTHOR]