Realization and Analysis of p-Type ZnO:Al Thin Film by RF Magnetron Sputtering

Hu-Jie Jin,Yun-Hwan Jeong,Choon-Bae Park 한국전기전자재료학회 2008 Transactions on Electrical and Electronic Material Vol.9 No.2

Al-doped p-type ZnO thin films were fabricated by RF magnetron sputtering on n-Si (100) and homo-buffer layers in pure oxygen ambient. ZnO ceramic mixed with 2 wt% Al₂O₃ was selected as a sputtering target. XRD spectra show that the Al-doped ZnO thin films have ZnO crystal structure. Hall Effect experiments with Van der Pauw configuration show that p-type carrier concentrations are arranged from 1.66x10^16 to 4.04x10^18 cm-², mobilities from 0.194 to 198 cm²V-¹s-¹ and resistivities from 0.0963 to 18.4 Wcm. FESEM cross section images of different parts of a p-type ZnO:Al thin film annealed at 800 0C show a compact structure. Measurement for same sample shows that density is 5.40 cm-³ which is smaller than theoretically calculated value of 5.67 cm-³. Photoluminescence (PL) spectra at 10 K show a shoulder peak of p-type ZnO film at about 3.117 eV which is ascribed to electron transition from donor level to acceptor level (DAP).

Defect Analysis via Photoluminescence of p-type ZnO:N Thin Film fabricated by RF Magnetron Sputtering

Jin, Hu-Jie,So, Soon-Jin,Park, Choon-Bae The Korean Institute of Electrical and Electronic 2007 전기전자재료학회논문지 Vol.20 No.3

ZnO is a promising material to make high efficient ultraviolet(UV) or blue light emitting diodes(LEDs) because of its large binding energy and energy bandgap. In this study, we prepared ZnO thin films with p-type conductivity on silicon(100) substrates by RF magnetron sputtering in the mixture of $N_2$ and $O_2$. The process was accompanied by low pressure in-situ annealing in $O_2$ at $600^{\circ}C$ and $800^{\circ}C$ respectively. Hall effect in Van der Pauw configuration showed that the N-doped ZnO film annealed at $800^{\circ}C$ has p-type conductivity. Photoluminescence(PL) spectrum of the film annealed at $800^{\circ}C$ showed UV emission related to exciton and bound to donor-acceptor pair(DAP) as well as visible emission related to many intrinsic defects.

Realization and Analysis of p-Type ZnO:Al Thin Film by RF Magnetron Sputtering

Jin, Hu-Jie,Jeong, Yun-Hwan,Park, Choon-Bae The Korean Institute of Electrical and Electronic 2008 Transactions on Electrical and Electronic Material Vol.9 No.2

Al-doped p-type ZnO thin films were fabricated by RF magnetron sputtering on n-Si (100) and homo-buffer layers in pure oxygen ambient. ZnO ceramic mixed with 2 wt% $Al_2O_3$ was selected as a sputtering target. XRD spectra show that the Al-doped ZnO thin films have ZnO crystal structure. Hall Effect experiments with Van der Pauw configuration show that p-type carrier concentrations are arranged from $1.66{\times}10^{16}$ to $4.04{\times}10^{18}\;cm^{-2}$, mobilities from 0.194 to $198\;cm^2V{-1}s^{-1}$ and resistivities from 0.0963 to $18.4\;{\Omega}cm$. FESEM cross section images of different parts of a p-type ZnO:Al thin film annealed at $800^{\circ}C$ show a compact structure. Measurement for same sample shows that density is $5.40\;cm^{-3}$ which is smaller than theoretically calculated value of $5.67\;cm^{-3}$. Photoluminescence (PL) spectra at 10 K show a shoulder peak of p-type ZnO film at about 3.117 eV which is ascribed to electron transition from donor level to acceptor level (DAP).

Positive Observer Design for Linear Impulsive Positive Systems with Interval Uncertainties and Time Delay

Meng-Jie Hu,Yan-Wu Wang,Jiang-Wen Xiao 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.3

This paper is concerned with the problem of positive observer design for impulsive positive systems(IPS) with interval uncertainties and time delay. A copositive Lyapunov-Krasovskii functional with exponentialterm is constructed. By applying the average impulsive interval method, sufficient conditions for the existence ofthe positive observer are established to guarantee the exponential stability of the corresponding augmented system,which ensures the designed positive observer can estimate the system states exponentially. Combined with the linearprogramming (LP) technique, an algorithm is developed to design the observer gain matrices. Finally, a numericalexample is provided to show the effectiveness of the theoretical results.

Sliding Mode Control for We-energy Based on Markovian Jumping Systems

Jingwei Hu,Qiuye Sun,Yan Zhao,Jie Hu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7

Sliding mode control (SMC) is a promising robust control approach for the abrupt variations in complexsystem. Energy internet (EI), as a dynamic nonlinear strong coupling system, has different operating states underdifferent operating conditions (system connection, load levels and faults, etc.). We-Energy (WE), as a basic energyunit in EI, is proposed for describing the essential characteristics and operating state of EI. According the operatingstates of EI, four operating modes of WE presented in this paper can be randomly converted, which correspond thestochastic markov process. Then, based on the coupling characteristics of EI, a set of state equations is establishedto embody the markovian jumping system (MJS) of WE. Moreover, sliding surface and contorl scheme for WEbased on MJS is designed. Finally, a numerical simulation is shown to illustrate the proposed method.

Prevalence, Risk Factors, and Psychological Effects of Primary Nocturnal Enuresis in Chinese Young Adults

Hui Jie Hu,Zhen Wei Zhang,Yu Liang,Yan Yan Luo,Qi Feng Dou,Cui Ping Song,Hui Min Zhang,Ying Zhao,Guang Run Tian,Ke Zhang,Qiu Fang Mao,Jing Gui Song,Soren Rittig,Jian Guo Wen 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.1

Purpose: This study aimed to investigate the prevalence, risk factors, and effects of primary nocturnal enuresis (PNE) on physical and mental health in young adults in mainland China. Methods: An anonymous questionnaire was used to collect information including the sociodemographic characteristics, history of PNE, family history, daytime voiding symptoms, Pittsburgh Sleep Quality Index (PSQI) scores, Self-Esteem Scale (SES), and Self-Rating Depression Scale (SDS). A total of 22,500 university students from 23 provinces and 368 cities in mainland China were included. Results: In total, 21,082 questionnaires were collected, and 20,345 of them qualified for statistical analysis. The PNE prevalence was 1.17%, and the distribution of monosymptomatic nocturnal enuresis (MNE) and nonmonosymptomatic nocturnal enuresis (NMNE) was 66.1% and 33.9%, respectively. In total, 28% of respondents with PNE reported bedwetting daily, 31.6% between 1 and 7 times weekly, and 40.4% between 1 and 4 times monthly; 80% of PNE cases had no history of treatment. The prevalence of PNE in patients with a family history, frequency, urgency, urinary incontinence, and recurrent urinary tract infections was significantly higher than in those without these conditions (P<0.001). PNE was significantly correlated with the PSQI total score (sleep quality) (P=0.011). The SES score was lower and the SDS was higher (P<0.001) in the PNE group than in those without PNE. Conclusions: In mainland China, the PNE prevalence among young adults was found to be high, and PNE had significant effects on physical and mental health. Risk factors included a family history, daytime voiding symptoms, and lack of treatment.

V-I Curves of p-ZnO:Al/n-ZnO:Al Junction Fabricated by RF Magnetron Sputtering

Jin, Hu-Jie,Jeong, Yun-Hwan,Park, Choon-Bae The Korean Institute of Electrical and Electronic 2008 전기전자재료학회논문지 Vol.21 No.6

Al-doped p-type ZnO films were fabricated on n-Si (100) and homo-buffer layers in pure oxygen at $450^{\circ}C$ of by RF magnetron sputtering. Target was ZnO ceramic mixed with 2 wt% $Al_2O_3$. XRD spectra show that the Al-doped ZnO thin films have ZnO crystal structure and homo-buffer layers are beneficial to Al-doped ZnO films to grow along c-axis. Hall Effect experiments with Van der Pauw configuration show that p-type carrier concentrations are ranged from $1.66{\times}10^{16}$ to $4.04{\times}10^{18}\;cm^{-3}$, mobilities from 0.194 to $2.3\;cm^2V^{-1}s^{-1}$ and resistivities from 7.97 to $18.4\;{\Omega}cm$. p-type sample has density of $5.40\;cm^{-3}$ which is smaller than theoretically calculated value of $5.67\;cm^{-3}$. XPS spectra show that Ols has O-O and Zn-O structures and Al2p has only Al-O structure. P-ZnO:Al/n-ZnO:Al junctions were fabricated by magnetron sputtering. V-I curves show that the p-n junctions have rectifying characteristics.

Mechanical behavior and sealing performance of HAR sealing system in roller cone bits

Yang Hu,Chuanjun Han,Jie Zhang,Zixuan Luo,Ruichuan Wang,Te Hu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

Two numerical models of HAR ring and O-ring sealing systems for roller cone bits were established in this paper. The stress-strain distribution was analyzed by finite element method. Effects of compression ratio, fluid pressure, ambient temperature and friction coefficient on mechanical behavior and sealing performance were studied. The results show that the HAR ring has better sealing performance than O-ring in the same working condition. The HAR ring can realize multi-stage sealing to increase the reliability of sealing. The high stress region appears at the sharp corner below the shaft. The sealing performance and the von Mises stress is enhanced with compression ratio and fluid pressure increasing. Under a high working temperature field, the sealing surface of HAR ring fails easily. The contact pressure fluctuation of the sealing surface easily appears by friction coefficient. Sharp-angled regions of the HAR ring near S.S.3, S.S.5 and S.S.6 fail easily.

Species Classification and Quality Assessment of Chaihu (Radix Bupleuri) Based on High-Performance Liquid Chromatographic Fingerprint and Combined Chemometrics Methods

Xiao-Jie Li,Jie Hu,Zhen-Yu Li,Xue-Mei Qin,Li-Zeng Zhang,Xiao-Qing Guo 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

A high-performance liquid chromatographic (HPLC) method was established to analyze 36 Chaihu (Radix Bupleuri) samples collected from three species (Bupleurum chinense DC., B. scorzonerifolium Willd. and B. smithii Wolff.). Addition of trifluoroacetic acid into the mobile phase resulted in fingerprint chromatograms with stable baselines. There were thirty-two characteristic peaks in the standard fingerprint of B. chinense DC. Different recognition pattern methods, including similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA) and partial least squares-discrimination analysis (PLS-DA) were utilized to analyze the 36 samples based on the contents of chemical constituents. Consistent results from SA, HCA and PCA analysis illustrated the rationalisation for why B. smithii Wolff. was not quoted in the Chinese Pharmacopoeia and classified samples were in agreement with their species. PLS-DA loading plots showed the chemical markers which had the most influences on the separation among different species. However, SA, HCA and PCA could not differentiate between wild and cultivated B. chinense DC. as well as between samples from different provinces. HPLC fingerprint in combination with chemometric techniques provided a very flexible and reliable method for homogeneity evaluation and quality assessment of traditional Chinese medicine.

A Reliable and Configurable E-commerce Mechanism based on Mobile Agents in Mobile Wireless Environments

Haiyang Hu,Hua Hu,Jie Chen 보안공학연구지원센터 2008 International Journal of Hybrid Information Techno Vol.1 No.1

Because of the limited capability of mobile devices and lower bandwidth of wireless network, Web-based e-commerce in mobile wireless environments suffers more challenges and it needs an efficient and reliable mechanism to support the process. This paper presents a flexible and configurable mechanism, which uses mobile agents as brokers of mobile device to communicate with Web server, thus to reduce the unnecessary wireless communication costs of mobile client. It can also facilitate mobile device recovery back when suffering a failure to increase the reliability of the whole application process. Compared with other mechanisms through performance analysis, our mechanism shows its efficiency and reliability.