Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials
66
Scopus Publications
Scopus Publications
Deconvoluting the transport mechanisms using electrical impedance spectroscopy in heterojunction organic solar cells doped with trimetallic nanospheres Baseerat Khan, Hakim Najeeb-ud-din Engineering Research Express, 2025 Nano-plasmonic structures have attracted the interest of researchers owing to their advantageous properties in solar cells. Ternary nanospheres lead to better charge conduction pathways, thereby reducing losses and boosting efficiency. The synergistic plasmonic effects of the tri-metallic nanospheres enable broader spectral absorption, making them superior for enhancing solar cell performance. This paper presents the simulation study of transportation mechanism and carrier kinetics in poly(3-hexylthiophene): [6,6]-phenyl-butyric acid methyl ester [P3HT: PCBM]-based organic solar cell doped with ternary nanospheres of silver, gold, and copper, which has not been explored prior. Critical electrical parameters, such as relaxation time, charge carrier mobility, diffusion time, flat-band voltage, and doping density, have been determined through AC analysis of the device. SETFOS, an instrumental one-dimensional tool, is used to determine these parameters using methods like impedance spectroscopy, Mott–Schottky analysis and Capacitance–Voltage modelling. This extensive examination allows for a better understanding of the device’s behaviour in the presence of ternary nanospheres. The tri-metallic nanoparticle-doped organic solar cells provide better performance parameters compared with the performance of an undoped solar cell. Further, circuit modelling of solar cells is done to facilitate the optimisation by allowing the simulation and prediction of performance parameters under various operating conditions.
Analytical modeling of contact resistance and recombination for silicon heterojunction solar cells using hybrid carrier selective passivating contacts Bisma Bilal, Hakim Najeeb-ud-Din Physica Scripta, 2024 Silicon heterojunction solar cells using Carrier Selective Passivating Contacts (CSPC) are the potential contenders for high efficiency next generation photovoltaics. Besides numerical simulations, the mathematical analysis of parameters affecting the performance of these cells is gaining considerable attention. In this work, the factors affecting the selectivity of silicon heterojunction solar cell using Hybrid Carrier Selective Passivating Contacts (H-CSPC) are investigated. This includes the evaluation of contact resistance and recombinations in the device. The contact resistance is analyzed in terms of partial resistances wherein an equivalent resistance model for the cell using H-CSPC is devised and resistances are inspected using quasi fermi level collapse over the contacts. The selectivity of the cell at each contact is examined and the condition for maximum selectivity is derived. Further, the recombinations in different regions of the cell using H-CSPC are analyzed. The recombinations at the TiO2/c-Silicon interface strongly deteriorate the V oc of the cell which is quantified using an analytical model under interface defect constraints and the results obtained are compared with simulations.
Analog-to-digital converters: a review of existing architectures and a new proposal for high resolution sensors Saima Bashir, Najeeb-ud-din Hakim, G.M. Rather Sensor Review, 2023 Purpose As technology advances the demand for an analog-to digital converter has increased, as every application demands a converter as per its parameters. Currently, work is done on improvement of data converters at three levels of design – architectural, circuit and physical level. This paper aims to review the work done in the field of analog-to-digital converters (ADCs) at architectural and circuit level and discusses the achievements in this field. Furthermore, a new architecture is proposed, which works at higher resolution and provides optimum design parameters at low power consumption. Design/methodology/approach A hybrid architecture combining the features of synthetic approximation register and sigma-delta ADC is presented. The validity of the proposed design at architectural level is verified using MATLAB SIMULINK simulations. Findings The design simulation was tested for a sinusoidal wave of 1 V at the test frequency of 60 Hz. The design consumes least power, and is found to yield an error of the order less than 10–3 V, thus providing highly accurate digital output. Originality/value The design is applicable in many applications including biomedical systems, Internet-of-Things and earthquake engineering. This architecture can be further optimized to obtain better performance parameters.
Thin film Single Halo (SH) SOI nMOSFETs - Short channel performance in mixed signal applications Proceedings of the IEEE Indicon 2004 1st India Annual Conference, 2004
Thin film single halo (SH) SOI nMOSFETs - Hot carrier reliability for mixed mode applications IEEE Region 10 Annual International Conference Proceedings TENCON, 2003
Characterization and simulation of lateral asymmetric channel Silicon-on-Insulator MOSFETs Proceedings of SPIE the International Society for Optical Engineering, 2002