Regulation of Electronic Properties of ZnO/In2O3 Heterospheres via Atomic Layer Deposition for High Performance NO2 Detection

CrystEngComm ◽  
2021 ◽  
Author(s):  
Zishuo Li ◽  
Chengming Lou ◽  
Guanglu Lei ◽  
Guocai Lu ◽  
Hongyin Pan ◽  
...  

Metal oxide semiconductor heterostructures are promising for gas sensors due to the unique chemical and electronic properties at the heterointerface. In this work, a highly sensitive and selective gas sensor...

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1552 ◽  
Author(s):  
Weber ◽  
Graniel ◽  
Balme ◽  
Miele ◽  
Bechelany

Improving the selectivity of gas sensors is crucial for their further development. One effective route to enhance this key property of sensors is the use of selective nanomembrane materials. This work aims to present how metal-organic frameworks (MOFs) and thin films prepared by atomic layer deposition (ALD) can be applied as nanomembranes to separate different gases, and hence improve the selectivity of gas sensing devices. First, the fundamentals of the mechanisms and configuration of gas sensors will be given. A selected list of studies will then be presented to illustrate how MOFs and ALD materials can be implemented as nanomembranes and how they can be implemented to improve the operational performance of gas sensing devices. This review comprehensively shows the benefits of these novel selective nanomaterials and opens prospects for the sensing community.


2015 ◽  
Vol 764-765 ◽  
pp. 138-142 ◽  
Author(s):  
Fa Ta Tsai ◽  
Hsi Ting Hou ◽  
Ching Kong Chao ◽  
Rwei Ching Chang

This work characterizes the mechanical and opto-electric properties of Aluminum-doped zinc oxide (AZO) thin films deposited by atomic layer deposition (ALD), where various depositing temperature, 100, 125, 150, 175, and 200 °C are considered. The transmittance, microstructure, electric resistivity, adhesion, hardness, and Young’s modulus of the deposited thin films are tested by using spectrophotometer, X-ray diffraction, Hall effect analyzer, micro scratch, and nanoindentation, respectively. The results show that the AZO thin film deposited at 200 °C behaves the best electric properties, where its resistance, Carrier Concentration and mobility reach 4.3×10-4 Ωcm, 2.4×1020 cm-3, and 60.4 cm2V-1s-1, respectively. Furthermore, microstructure of the AZO films deposited by ALD is much better than those deposited by sputtering.


2012 ◽  
Vol 24 (7) ◽  
pp. 1255-1261 ◽  
Author(s):  
Xinyi Chen ◽  
Ekaterina Pomerantseva ◽  
Parag Banerjee ◽  
Keith Gregorczyk ◽  
Reza Ghodssi ◽  
...  

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Yin ◽  
Lian Liu ◽  
Yashu Zang ◽  
Anni Ying ◽  
Wenjie Hui ◽  
...  

AbstractHere, an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on the graphene/silicon heterojunction photodetectors. With considering the suitable band structure of the insulation material and their special defect states, an atomic layer deposition (ALD) prepared wide-bandgap insulating (WBI) layer of AlN was introduced into the interface of graphene/silicon heterojunction. The promoted tunneling process from this designed structure demonstrated that can effectively help the impact ionization with photogain not only for the regular minority carriers from silicon, but also for the novel hot carries from graphene. As a result, significantly enhanced photocurrent as well as simultaneously decreased dark current about one order were accomplished in this graphene/insulation/silicon (GIS) heterojunction devices with the optimized AlN thickness of ~15 nm compared to the conventional graphene/silicon (GS) devices. Specifically, at the reverse bias of −10 V, a 3.96-A W−1 responsivity with the photogain of ~5.8 for the peak response under 850-nm light illumination, and a 1.03-A W−1 responsivity with ∼3.5 photogain under the 365 nm ultraviolet (UV) illumination were realized, which are even remarkably higher than those in GIS devices with either Al2O3 or the commonly employed SiO2 insulation layers. This work demonstrates a universal strategy to fabricate broadband, low-cost and high-performance photo-detecting devices towards the graphene-silicon optoelectronic integration.


Nanoscale ◽  
2021 ◽  
Author(s):  
Soon-Hwan Kwon ◽  
Tae-Hyeon Kim ◽  
Sang-Min Kim ◽  
Semi Oh ◽  
Kyoung-Kook Kim

Nanostructured semiconducting metal oxides such as SnO2, ZnO, TiO2, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors,...


Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2123 ◽  
Author(s):  
Wenli Li ◽  
Yong Zhang ◽  
Xia Long ◽  
Juexian Cao ◽  
Xin Xin ◽  
...  

The unique properties of MoS2 nanosheets make them a promising candidate for high-performance room temperature gas detection. Herein, few-layer MoS2 nanosheets (FLMN) prepared via mechanical exfoliation are coated on a substrate with interdigital electrodes for room-temperature NO2 detection. Interestingly, compared with other NO2 gas sensors based on MoS2, FLMN gas sensors exhibit high responsivity for room-temperature NO2 detection, and NO2 is easily desorbed from the sensor surface with an ultrafast recovery behavior, with recovery times around 2 s. The high responsivity is related to the fact that the adsorbed NO2 can affect the electron states within the entire material, which is attributed to the very small thickness of the MoS2 nanosheets. First-principles calculations were carried out based on the density functional theory (DFT) to verify that the ultrafast recovery behavior arises from the weak van der Waals binding between NO2 and the MoS2 surface. Our work suggests that FLMN prepared via mechanical exfoliation have a great potential for fabricating high-performance NO2 gas sensors.


2019 ◽  
Vol 9 (11) ◽  
pp. 2388 ◽  
Author(s):  
Chao Zhao ◽  
Jinjuan Xiang

The continuous down-scaling of complementary metal oxide semiconductor (CMOS) field effect transistors (FETs) had been suffering two fateful technical issues, one relative to the thinning of gate dielectric and the other to the aggressive shortening of channel in last 20 years. To solve the first issue, the high-κ dielectric and metal gate technology had been induced to replace the conventional gate stack of silicon dioxide layer and poly-silicon. To suppress the short channel effects, device architecture had changed from planar bulk Si device to fully depleted silicon on insulator (FDSOI) and FinFETs, and will transit to gate all-around FETs (GAA-FETs). Different from the planar devices, the FinFETs and GAA-FETs have a 3D channel. The conventional high-κ/metal gate process using sputtering faces conformality difficulty, and all atomic layer deposition (ALD) of gate stack become necessary. This review covers both scientific and technological parts related to the ALD of metal gates including the concept of effect work function, the material selection, the precursors for the deposition, the threshold voltage (Vt) tuning of the metal gate in contact with HfO2/SiO2/Si. The ALD of n-type metal gate will be detailed systematically, based mainly on the authors’ works in last five years, and the all ALD gate stacks will be proposed for the future generations based on the learning.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
J. H. Yum ◽  
J. Oh ◽  
Todd. W. Hudnall ◽  
C. W. Bielawski ◽  
G. Bersuker ◽  
...  

In a previous study, we have demonstrated that beryllium oxide (BeO) film grown by atomic layer deposition (ALD) on Si and III-V MOS devices has excellent electrical and physical characteristics. In this paper, we compare the electrical characteristics of inserting an ultrathin interfacial barrier layer such as SiO2, Al2O3, or BeO between the HfO2gate dielectric and Si substrate in metal oxide semiconductor capacitors (MOSCAPs) and n-channel inversion type metal oxide semiconductor field effect transistors (MOSFETs). Si MOSCAPs and MOSFETs with a BeO/HfO2gate stack exhibited high performance and reliability characteristics, including a 34% improvement in drive current, slightly better reduction in subthreshold swing, 42% increase in effective electron mobility at an electric field of 1 MV/cm, slightly low equivalent oxide thickness, less stress-induced flat-band voltage shift, less stress induced leakage current, and less interface charge.


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