An E-mode p-channel GaN MOSHFET for a CMOS compatible PMIC

The operation principle of a low power E-mode p-channel GaN MOSHFET is explained via TCAD simulations. The challenges of achieving negative threshold voltage with the scaling of gate length are addressed by adjusting the mole fraction of an AlGaN cap layer beneath the gate. An inverter consisting of the proposed p-channel GaN MOSHFET with a gate length of 025 μm shows promise of a CMOS compatible Power Management IC in the MHz range

Extending the bounds of performance in E-mode p-channel GaN MOSHFETs

An investigation of the distribution of the electric field within a normally-off p-channel heterostructure field-effect transistor in GaN, explains why a high |Vth| requires a reduction of the thickness of oxide and the GaN channel layer. The trade-off between on-current |Ion| and |Vth|, responsible for the poor |ION| in E-mode devices is overcome with an additional cap AlGaN layer that modulates the electric field in itself and the oxide. A record |Ion| of 50-60 mA/mm is achieved with a |Vth| greater than |-2| V in the designed E-mode p-channel MOSHFET, which is more than double that in a conventional device

A p-channel GaN heterostructure tunnel FET with high ON/OFF current ratio

A novel mechanism to achieve a nonambipolar tunnel FET (TFET) is proposed in this paper. The method relies on polarization charge induced in semiconductors, such as group III nitrides, to enhance the electric field across the junction and facilitate unidirectional tunneling based on the polarity of the applied gate bias. This also enables enhanced control over the tunneling distance, reducing it significantly in comparison to a conventional TFET. The proposed p-channel device implemented in a novel vertical GaN nanowire geometry facilitates a reduction of footprint while still maintaining comparable performance to that of conventional E-mode p-channel devices in GaN. This opens up possibilities for E-mode p-channel GaN devices

Appraisal of phytochemical and antibacterial potential of Myrica nagi Willd. extracts against respiratory tract pathogens

In the present study the antibacterial activity was studied against five bacterial pathogens i.e. Haemophilus influenzae MTCC 3826, Pseudomonas aeruginosa MTCC 2474, Staphylococcus aureus MTCC 1144, Streptococcus pneumoniae MTCC 655 and Streptococcus pyogenes MTCC 442. Shade dried root were crushed and extracted in petroleum ether (PET), acetone (ACE), methanol (MeOH) and water (H2O) by using Soxhlet apparatus. The agar well diffusion method was adopted to examine antibacterial activity of extracts against the susceptible organisms. Erythromycin was used as positive control to determine the sensitivity of the strains. Phytochemical analysis was done for plant extract. The results showed that MeOH extract was most active as comparison to other extract. The maximum inhibition was found against H. influenzae (18.4±0.07 mm) followed by S. pyogenes (17.3±0.13 mm), S. pneumoniae (16.2±0.07 mm) and P. aeruginosa (15.5±0.15 mm) respectively. The minimum inhibition was noted against S. aureus (14.4±0.13 mm). The phytochemical screening for MeOH extract has shown that plant contains flavonoids, glycosides, alkaloids, steroids, terpene, saponins and tannins. Therefore, M. nagi can be helpful as an alternative source of medicine and new drug discovery

An ultralow power 3-terminal memory device with write capability in the off-state

In this work, we demonstrated a room temperature fabricated ZnO/Ta 2 O 5 transistor for low power compute-in-memory application. By writing during the off-state, the device programmed for compute-in-memory shows power consumption in nW. By using variable pulse amplitudes for SET/RESET allows control of the on/off ratio of resistance states without affecting power consumption. Benchmarked against other ReRAMs the device shows a competitive 8 nJ per transition, which allows a reduction of power consumption in comparison to a filamentary device

Rapid Detection of Ricin by Sensitising Carboxylated Latex Particles by Ricin Antibodies

Ricin is a highly toxic glycoprotein of Ricinus communis seeds. The toxin was purified and antisera was raised against ricin in rabbit. Polyclonal antibodies were covalently coupled througha water soluble carbodiimide to carboxylated latex particles in various concentrations (800 pg to 3200 pg proteid0.5 ml). Maximum antibodies binding was obtained at 2400 pg to 3200 pgproteid0.5 ml of 2 per cent (wtlvol) latex particles with a sensitivity of 200 pg toxin per test (9 pglml). The sensitivity of latex agglutination test increased as amount of protein bound tothe latex particles increased. The optimum sensitivity of test was recorded when latex particles were sensitised with 2800 pg proteid0.5 ml of latex particles. The reagents were stable for one year without loss of its sensitivity. Developed latex agglutination test is rapid, sensitive, and also does not require trained personnel and costly equipment

Prospects and Present Status and of Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) in Nepal

Naturally occurring entomopathogenic nematodes(EPN) and their symbiotic bacteria are important biotic factor in suppression of insect pest populations in soil and cryptic habitats. These nematodes can control pests due to their mutualistic association with bacteria that kill the hosts by septicemia and make the environment favorable for EPN development and reproduction.The virulent species of EPN can commercially be mass produced as biological control agents all over the world. Nepal  has a great potential to exploit these beneficial nematodes for the control of insect pests. Exploration of indigenous EPN is receiving attention around th eworld. Numerous surveys conducted worldwide have detected many indigenous isolates. Altogether 115 species of EPN (97 of Steinernema and 18 of Heterorhabdits species) have been reported so far worldwide. However, very limited research on EPN in Nepal has been done with 29 species only with some new species. Hence,the isolation and description of the native efficacious species and populationsof EPN is the need of the hour,not only from a biodiversity view point but also from an environmental and biological control perspective.Thei dentification of EPNs, adapted to environmental and climatic conditions of cultivated areas, is important for sustainable pest suppression in integrated management programs in agricultural areas of Nepal. This article provides an overview of recent development on EPN research and evaluates their potential for use and exploitation in Nepal

Impact of channel thickness on the performance of an E-mode p-channel MOSHFET in GaN

Introduction of positive polarization charge by utilising an AlGaN cap layer between the gate oxide and the channel is one of the promising techniques to deplete a two-dimensional hole gas (2DHG) to achieve an E-mode p-channel GaN MOSHFET. The results from TCAD simulations indicate that the off-state leakage increases by orders of magnitude for channel layers thicker than 20 nm in this structure. Biasing the two-dimensional electron gas beneath the 2DHG helps alleviate this limitation at the cost of reducing on-current. Scaling the access regions and combining the two techniques allow maximum benefit in terms of on-state current, negative threshold voltage, and the on/off current ratio