Zishuo Li

Bio: Zishuo Li is an academic researcher from Qingdao University. The author has contributed to research in topics: Materials science & Thin film. The author has an hindex of 4, co-authored 9 publications receiving 75 citations.

Thin films of tungsten oxide materials for advanced gas sensors

Abstract: Thin film technology shows high promise in fabrication of electronic devices such as gas sensors. Tungsten trioxide (WO3), as one of the best-known metal oxide semiconductors (MOS) sensing materials, has attracted significant interest for application in gas sensors. In this review, WO3 thin films and their promising utilization as the sensing layers are overviewed to highlight their potential in gas sensors. First, the sensing mechanism for WO3 materials is briefly discussed. Then, several methods for WO3 film preparation are summarized. Following we discuss the specific gas sensing performances of WO3 film sensors to NO2, H2, NH3, and H2S. Strategies to improve the sensor properties such as sensitivity, response-recovery speed and selectivity are also discussed. Finally, the future perspectives and challenges of WO3 thin film sensors are addressed.

Rational design of ordered porous SnO2/ZrO2 thin films for fast and selective triethylamine detection with humidity resistance

Abstract: Current gas sensors based on metal oxide semiconductors still suffer greatly from the poor selectivity and low tolerance to the high relative humidity (RH) Herein, we report a highly selective and humidity-resistant gas sensor based on SnO2/ZrO2 porous thin films with a three-dimensionally ordered microstructure (3DOM) The 3DOM ZrO2 fabricated by a template method serves as a hydrophobic layer and SnO2 deposited on ZrO2 by atomic layer deposition (ALD) acts as the transducer layer Gas sensing tests reveal the SnO2/ZrO2 sensor has a decent response to triethylamine (TEA), a highly toxic and flammable chemical widely used in industry The sensor exhibits an ultrafast response and recovery (∼ 1 s) speed to 20 ppm TEA at an optimum operating temperature of 190 °C When the RH increases from 50 % to 90 %, the response of SnO2/ZrO2 sensor shows a minor decrease of 18 %, which to our best knowledge surpasses the existing reports on TEA detection under high RH The humidity resistance is attributed to continuous 3DOM ZrO2 layers, which forms an air hydrophobic layer to suppress water adsorption Furthermore, the SnO2/ZrO2 sensor also possesses superior selectivity, long-time stability and a low detection limit of 40 ppb, thereby endowing a potential toward practical TEA detection

Anchoring Fe2O3 nanosheets on NiO nanoprisms to regulate the electronic properties for improved n-butanol detection

Abstract: Metal oxide heterostructures have great potential in gas sensor devices due to the attractive chemical and electronic properties at the heterogeneous interfaces. Herein, a unique heterostructure of NiO nanoprisms/Fe 2 O 3 nanosheets is rationally designed by a solution method for use in n-butanol sensors with superior performances. Mott-Schottky tests reveal that the conductivity of the NiO sensor transforms from p-type to n-type after growing Fe 2 O 3. This conversion of conductivity plays a crucial role in improving the sensor response, which overcomes the low response of p-type metal oxides. The sensor shows good linear response within the concentration range of 0.1–20 ppm n-butanol under operating temperatures (Room Temperature-320 °C). Gas sensing investigations show the sensor based on NiO/Fe 2 O 3 has a response of 4.2–10 ppm n-butanol at an optimal temperature of 200 °C, revealing a 3-time enhancement compared to pure NiO. Meanwhile the NiO/Fe 2 O 3 sensor exhibits a detection limit of 48 ppb, which is much lower than that (296 ppb) of NiO. The proposed structural design in this work provides a new idea for synthesis of high-performance sensing materials for the detection of ppb-level n-butanol. • Fe 2 O 3 nanosheets are grown on NiO nanoprisms by wet-chemical method. • Fe 2 O 3 nanosheets improve the adsorption of reactive oxygen on NiO nanoprisms. • The NiO/Fe 2 O 3 heterostructures exhibit fast response for n-butanol detection. • The NiO/Fe 2 O 3 sensor delivers good selectivity and low detection limit to n-butanol.

Black Phosphorus Field-effect Transistors

Abstract: Two-dimensional crystals have emerged as a class of materials that may impact future electronic technologies. Experimentally identifying and characterizing new functional two-dimensional materials is challenging, but also potentially rewarding. Here, we fabricate field-effect transistors based on few-layer black phosphorus crystals with thickness down to a few nanometres. Reliable transistor performance is achieved at room temperature in samples thinner than 7.5 nm, with drain current modulation on the order of 10(5) and well-developed current saturation in the I-V characteristics. The charge-carrier mobility is found to be thickness-dependent, with the highest values up to ∼ 1,000 cm(2) V(-1) s(-1) obtained for a thickness of ∼ 10 nm. Our results demonstrate the potential of black phosphorus thin crystals as a new two-dimensional material for applications in nanoelectronic devices.

Thin films of tungsten oxide materials for advanced gas sensors

Abstract: Thin film technology shows high promise in fabrication of electronic devices such as gas sensors. Tungsten trioxide (WO3), as one of the best-known metal oxide semiconductors (MOS) sensing materials, has attracted significant interest for application in gas sensors. In this review, WO3 thin films and their promising utilization as the sensing layers are overviewed to highlight their potential in gas sensors. First, the sensing mechanism for WO3 materials is briefly discussed. Then, several methods for WO3 film preparation are summarized. Following we discuss the specific gas sensing performances of WO3 film sensors to NO2, H2, NH3, and H2S. Strategies to improve the sensor properties such as sensitivity, response-recovery speed and selectivity are also discussed. Finally, the future perspectives and challenges of WO3 thin film sensors are addressed.

Gas sensing performance of 2D nanomaterials/metal oxide nanocomposites: a review

Abstract: In recent years, the utilization of gas sensors has increased tremendously in daily life and industry. Importantly, appropriate material selection should be made for gas sensors in order to achieve outstanding gas sensing performance, such as high sensitivity, good selectivity, a fast response/recovery time, and long-term stability. Numerous studies have shown that neither pure metal oxide semiconductor nor individual 2D nanomaterial (graphene, transition metal dichalcogenides, metal–organic frameworks, metal oxide nanosheets, MXenes, and phosphorene) based gas sensors are capable of showing excellent gas-sensing performance towards gas molecules. However, synergistic combinations of metal oxides and 2D nanomaterials have demonstrated enhanced gas-sensing performance in many studies. This review aims at providing a comprehensive summary of the current advancements in 2D/metal-oxide based heterostructures as gas sensors. Additionally, the underlying sensing mechanisms of various kinds of gas sensors are systematically described, and the device architectures and their corresponding sensing performances are summarized. Finally, the challenges and future prospects of 2D/metal-oxide nanocomposite-based gas sensors for sensing applications have been outlined.