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Characterization of electrical properties of Algan/gan interface using coupled Schrodinger and Poisson equation

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Journal of Semiconductors 2012年第11期33卷 16-23页

作者： S.Das A.K.Panda g.n.dash national Institute of Science and Technology Palur HillsBerhampurOdisha761008India

The electrical characterization of Algan/gan interface is *** dependence of two-dimensional electron gas（2-DEg） density at the interface on the Al mole fraction and thickness of AIgan layer as well as on the thickness of gan cap layer is *** information can be used to design and fabricate Algan/gan based MODFET（modulation doped field effect transistor） for optimum DC and RF characteristics.

关键词： MODFET 2-DEg polarization critical thickness self-heating

RF and microwave characteristics of a 10 nm thick Ingan-channel gate recessed HEMT

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Journal of Semiconductors 2013年第11期34卷 36-41页

作者： T.R.Lenka g.n.dash A.K.Panda Department of Electronics and Communication Engineering National Institute of Technology Silchar School of Physics Sambalpur University national Institute of Science and Technology

A new depletion-mode gate recessed A1gan/Ingan/gan-high electron mobility transistor （HEMT） with 10 nm thickness of Ingan-channel is proposed. A growth of A1gan over gan leads to the formation of two- dimensional electron gas （2DEg） at the heterointerface. High 2DEg density （ns） is achieved at the heterointerface due to a strain induced piezoelectric effect between A1gan and gan layers. The electrons are confined in the Ingan-channel without spilling over into the buffer layer, which also reduces the buffer leakage current. From the input transfer characteristics the threshold voltage is obtained as -4.5 V and the device conducts a current of 2 A/mm at a drain voltage of 10 V. The device also shows a maximum output current density of 1.8 A/ram at Vds of 3 V. The microwave characteristics like transconductance, cut-off frequency, max frequency of oscillation and Mason＇s Unilateral gain of the device are studied by AC small-signal analysis using a two-port network. The stability and power performance of the device are analyzed by the Smith chart and polar plots respectively. To our knowledge this proposed Ingan-channel HEMT structure is the first of its kind.

关键词： 2DEg HEMT Ingan microwave

Effect of tunneling current on the noise characteristics of a 4H-SiC Read Avalanche diode

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Journal of Semiconductors 2013年第1期34卷 23-27页

作者： Deepak K.Karan Pranati Panda g. n.dash School of Physics Sambalpur UniversityJyoti ViharBurlaSambalpur-768 019 (Odisha)India

noise characteristics of a Read Avalanche diode are analyzed by incorporating the tunneling mechanism of the electron into the avalanche *** expressions are presented for the mean square noise voltage and noise measure in MITATT（mixed tunneling and avalanche transit time） mode operation.A wide band gap semiconductor（4H-SiC） based MITATT diode is considered to study the effect of tunneling on the noise characteristics and negative *** exhibiting enough potential for 4H-SiC to be used as a terahertz source of power in the MITATT mode,our results record a noise measure of 35.18 dB at a frequency of 1.5 THz.

关键词： MITATT 4H-SiC noise

Low noise wide bandgap SiC based IMPATT diodes at sub-millimeter wave frequencies and at high temperature

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Journal of Semiconductors 2014年第3期35卷 50-55页

作者： J.Pradhan S.R.Pattanaik S.K.Swain g.n.dash School of Physics Sambalpur University Jyoti Vihar Burla Sambalpur Odisha 767019 India Apex Institute of Technology and Management Bhubaneswar Odisha 752101 India

We have presented a comparative account of the high frequency prospective as well as noise behaviors of wide-bandgap 4H-SiC and 6H-SiC based on different structures of IMPATT diodes at sub-millimeter-wave frequencies up to 2.18 THz. The computer simulation study establishes the feasibility of the SiC based IMPATT diode as a high power density terahertz source. The most significant feature lies in the noise behavior of the SiC IMPATT diodes. It is noticed that the 6H-SiC DDR diode shows the least noise measure of 26.1 dB as compared to that of other structures. Further, it is noticed that the noise measure of the SiC IMPATT diode is less at a higher operating frequency compared to that at a lower operating frequency.

关键词： IMPATT silicon carbide terahertz(THz) science

A sensitivity analysis of millimeter wave characteristics of SiC IMPATT diodes

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Journal of Semiconductors 2017年第6期38卷 58-65页

作者： S K Swain J Pradhan g n dash S R Pattanaik School of Physics Sambalpur University Sambalpur Odisha 767019 India College of Engineering Bhubaneswar Bhubaneswar Odisha 751024 India national Institute of Science and Technology Berhampur Odisha 761008 India

Ionization rate coefficients and saturation drift velocities for electrons and holes are the vital material parameters in determining the performance of an IMPATT *** have performed a sensitivity analysis of the millimeter wave characteristics of 4H-SiC and 6H-SiC IMPATT diodes with reference to the above mentioned material data and an operating frequency of 220 *** effect of a small variation in the ionization rate and drift velocity on the device characteristics like break down voltage,efficiency,noise measure and power output has been presented here.

关键词： IMPATT SiC ionization rate saturation drift velocity, millimeter wave

Potentials of gaP as millimeter wave IMPATT diode with reference to Si,gaAs and gan

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红外与毫米波学报 2019年第4期38卷 395-402页

作者： Janmejaya Pradhan S K Swain S R Pattnaik g n dash College of Engineering Bhubaneswar Bhubaneswar Odisha 752024 India national Institute of Science and Technology Berhampur Odisha 761008 India School of Physics Sambalpur University Sambalpur Odisha 768019 India

This paper presents the simulation results of DC,small-signal and noise properties of gaP based Double Drift Region( DDR) Impact Avalanche Transit Time( IMPATT) diodes. In simulation study we have considered the flat DDR structures of IMPATT diode based on gaP,gaAs,Si and gan( wurtzite,wz) material. The diodes are designed to operate at the millimeter window frequencies of 94 gHz and 220 gHz. The simulation results of these diodes reveal gaP is a promising material for IMPATT applications based on DDR structure with high break down voltage( V_B) as compared to Si and gaAs IMPATTs. It is also encouraging to worth note gaP base IMPATT diode shows a better output power density of 4. 9 × 10~9 W/m^2 as compared to Si and gaAs based IMPATT diode. But IMPATT diode based on gan( wz) displays large values of break down voltage,efficiency and power density as compared to Si,gaAs and gaP IMPATTs.

关键词： lmpact avalanche transit time(IMPATT) gaP gan microwave and millimetre wave

Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina Hromada Patrick Heimel Markus Kerbl Lászlógál Sylvia nürnberger Barbara Schaedl James Ferguson nicole Swiadek Xavier Monforte Johannes C.Heinzel Antal nógrádi Andreas H.Teuschl-Woller David Hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria Ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of Hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tngCs). However, the use of tngCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tngC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tngCs and compared the various features of these improved silk^(+) tngCs with the tubes without holes(silk^(–) tngCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tngCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tngCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tngCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tngCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

nucleoside modified mRnA-lipid nanoparticles as a new delivery platform for the repair of the injured spinal cord

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neural Regeneration Research 2025年第8期20卷 2311-2312页

作者： Krisztián Pajer Tamás Bellák Antal nógrádi Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary

Spinal cord injury and treatment opportunities:The adult mammalian spinal cord has a very limited capacity for spontaneous regeneration due to various intrinsic molecular and cellular *** the spinal cord neurons have the capacity to regenerate their axons,the expression of growth inhibitory factors,lack or suppression of proper guidance cues,and profound inflammatory responses do not permit successful regeneration(Khyeam et al.,2021).

关键词： injured capacity modified

growth promoting effect of microbial inoculants on Acacia nilotica grown under nursery conditions

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Studies in Fungi 2021年第1期6卷 400-407页

作者： dash S gupta n Plant Pathology and Microbiology Division Regional Plant Resource CentreBhubaneswar-751015 OdishaIndia

Present study was carried out on Acacia nilotica seedlings grown under different bioinoculation treatments by using laboratory grown liquid cultures of 10 fungal isolates,11 Rhizobium isolates and 5 other bacterial *** cultures were screened for their effects on growth of Acacia nilotica grown in greenhouse *** selected microbial inoculants were assessed as considering their individual performance or in combination with the other inoculants in specific *** higher performance was shown with the combination of Penicillum chrysogenum Thom.1,B 5 bacterial isolate,R10 and/or R11 isolates of ***,it was observed that the above microbial mixed culture inoculation was promoted plant growth specifically number of leaves and the leaf ***,nursery application of mixed microbial inoculants,specifically as above could be beneficial for the production of quality planting material(QPM)of Acacia nilotica and subsequent field applications.

关键词： Acacia nilotica Aspergillus growth Penicillium Phosphate solubilization Rhizobium