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: Quantum efficiency & Diode. The organization has 618 authors who have published 940 publications receiving 10674 citations.

Compositionally graded AlGaN hole source layer for deep-ultraviolet nanowire light-emitting diode without electron blocking layer.

Abstract: The electron blocking layer (EBL) plays a vital role in blocking the electron overflow from an active region in the AlGaN-based deep-ultraviolet light-emitting diode (DUV-LED). Besides the blocking of electron overflow, EBL reduces hole injection toward the active region. In this work, we proposed a DUV nanowire (NW) LED structure without EBL by replacing it with a compositionally continuous graded hole source layer (HSL). Our proposed graded HSL without EBL provides a better electron blocking effect and enhanced hole injection efficiency. As a result, optical power is improved by 48% and series resistance is reduced by 50% with 4.8 V threshold voltage. Moreover, graded HSL without EBL offer reduced electric field within the active region, which leads to a significant increment in radiative recombination rate and enhancement of spontaneous emission by 34% at 254 nm wavelength, as a result, 52% maximum internal quantum efficiency with 24% efficiency drop is reported.

Experimental study to explore the 8 Be-induced nuclear reaction via the Trojan horse method

Abstract: To explore a possible indirect method for $^{8}\mathrm{Be}$ induced astrophysical reactions, the $^{9}\mathrm{Be}=(^{8}\mathrm{Be}+\mathit{n})$ cluster structure has been studied via the Trojan horse method. For the first time a $^{8}\mathrm{Be}$ nucleus having an ultrashort lifetime is studied by the Trojan horse method and a $^{9}\mathrm{Be}$ nucleus in the ground state is used for this purpose. The $^{9}\mathrm{Be}$ nucleus is assumed to have a ($^{8}\mathrm{Be}+\mathit{n}$) cluster structure and used as a Trojan horse nucleus. The $^{8}\mathrm{Be}$ nucleus acts as a participant, while the neutron is a spectator to the virtual $^{8}\mathrm{Be}+\mathit{d}\ensuremath{\rightarrow}\ensuremath{\alpha}+^{6}\mathrm{Li}$ reaction via the 3-body reaction $^{9}\mathrm{Be}+\mathit{d}\ensuremath{\rightarrow}\ensuremath{\alpha}+^{6}\mathrm{Li}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}\mathit{n}$. The experimental neutron momentum distribution inside $^{9}\mathrm{Be}$ has been reconstructed. The agreement between the experimental momentum distribution and the theoretical one indicates that a ($^{8}\mathrm{Be}+\mathit{n}$) cluster structure inside $^{9}\mathrm{Be}$ is very likely. Therefore, the experimental study of $^{8}\mathrm{Be}$ induced reactions, for example, the measurement of the $^{8}\mathrm{Be}+\ensuremath{\alpha}\ensuremath{\rightarrow}^{12}\mathrm{C}$ reaction proceeding through the Hoyle state, is possible.

Study of Gamow–Teller strength and associated weak-rates on odd-A nuclei in stellar matter

Abstract: In a recent study by Cole et al. [A. L. Cole et al., Phys. Rev. C 86 (2012) 015809], it was concluded that quasi-particle random phase approximation (QRPA) calculations show larger deviations and overestimate the total experimental Gamow–Teller (GT) strength. It was also concluded that QRPA calculated electron capture rates exhibit larger deviation than those derived from the measured GT strength distributions. The main purpose of this study is to probe the findings of the Cole et al. paper. This study gives useful information on the performance of QRPA-based nuclear models. As per simulation results, the capturing of electrons that occur on medium heavy isotopes have a significant role in decreasing the ratio of electron-to-baryon content of the stellar interior during the late stages of core evolution. We report the calculation of allowed charge-changing transitions strength for odd-A fp-shell nuclei (45Sc and 55Mn) by employing the deformed pn-QRPA approach. The computed GT transition strength is compa...

Frequency component vectorisation for image dehazing

Abstract: Image captured in bad weather conditions confines scene prominence, appears grey and diminishes image contrast. This usually happens due to atmospheric dispersing phenomenon that affects the qualit...