Ghulam Ishaq Khan Institute of Engineering Sciences and Technology

About: Ghulam Ishaq Khan Institute of Engineering Sciences and Technology is a education organization based out in Topi, Pakistan. It is known for research contribution in the topics: Thin film & Quantum efficiency. The organization has 618 authors who have published 940 publications receiving 10674 citations.

Printing an ITO-free flexible poly (4-vinylphenol) resistive switching device

Abstract: Resistive switching in a sandwich structure of silver (Ag)/Polyvinyl phenol (PVP)/carbon nanotube (CNTs)-silver nanowires (AgNWs) coated on a flexible PET substrate is reported in this work. Densely populated networks of one dimensional nano materials (1DNM), CNTs-AgNWs have been used as the conductive bottom electrode with the prominent features of high flexibility and low sheet resistance of 90 Ω/sq. Thin, yet uniform active layer of PVP was deposited on top of the spin coated 1DNM thin film through state of the art printing technique of electrohydrodynamic atomization (EHDA) with an average thickness of 170 ± 28 nm. Ag dots with an active area of ∼0.1 mm2 were deposited through roll to plate printing system as the top electrodes to complete the device fabrication of flexible memory device. Our memory device exhibited suitable electrical characteristics with OFF/ON ratio of 100:1, retention time of 60 min and electrical endurance for 100 voltage sweeps without any noticeable decay in performance. The resistive switching characteristics at a low current compliance of 3 nA were also evaluated for the application of low power consumption. This memory device is flexible and can sustain more than 100 bending cycles at a bending diameter of 2 cm with stable HRS and LRS values. Our proposed device shows promise to be used as a future potential nonvolatile memory device in flexible electronics.

AlGaN-based ultraviolet light-emitting diodes: challenges and opportunities

Abstract: Due to low power consumption, tunable wavelength and long lifetime ultraviolet light-emitting diodes (UV LEDs) have found many applications in different fields such as health care, water disinfection, agriculture. In this review, we report different problems that lead to low external quantum efficiency of UV LEDs. We also report various challenges in the growth process of the UV LEDs such as increase in the dislocation density, which affects the optoelectronic performance of the devices. We also report the analysis of the two modes of light polarization, i.e. transverse electric and transverse magnetic in UV LEDs. Moreover, we also summarize various state-of-the-art reported external quantum efficiencies, light output power and peak emission wavelengths in the three UV wavelength regimes, i.e. UV-A, UV-B and UV-C LEDs.

Antidiabetic properties of phytosynthesized gold nanoparticles (AuNPs) from Datura stramonium seed

Abstract: The gold nanoparticles synthesized from Datura stramonium seed was investigated for its antidiabetic properties in the present study. A total number of 42 healthy male albino rats with body weight ranges of 150±20 g were purchased and 7 days acclimatization was carried out after which they were randomly divided into 7 groups (A-G) of 6 animals each. Group A, the control was not induced while the other six groups (B-G) were induced with 150 mg/kg of alloxan by intraperitoneal administration. After 72 h, measurement of the tail vein blood glucose was done to confirm hyperglycemia. Experimental rats with fasting glucose levels (5.6-6.9 mmol/l) were considered diabetic. Group B received no treatment, Group C received 1000 μg/kg of Datura stramonium seed extract, Group D received 500 μg/ml of synthesized AuNPs, Group E received 750 μg/ml of synthesized AuNPs, Group F received 1000 μg/ml of synthesized AuNPs and Group G received 1000 μg/ml of standard drug (glibenclamide). This treatment was administered every day for 21 days. The result showed that the weight of the rats reduced after diabetes induction but after 21 days of treatment, the weight of the treated groups increased when compared to the untreated group. Furthermore, it was observed that after the treatment with 500 and 750 μg/ml AuNPs, the blood sugar was down regulated unlike the untreated groups. Due to the alloxan induction, there were increases in aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea and creatinine levels in the serum of experimental rats, which were significantly reduced after the treatment with Datura stramonium seed extract and the synthesized nanoparticles at 500, 750 and 1000 μg/ml. The histopathology of the pancreas of alloxan induced rats showed severe fibrotic interlobular connective tissues with severely diffused, degenerated, and necrotized Islets of langerhans which were also normalized by treatments with AuNPs. It was confirmed in this research that AuNPs could be embedded in drugs or folk medicine aimed at reducing blood sugar levels.