Nur Irwany Ahmad
Thumbnail Image
Preferred name
Nur Irwany Ahmad
Official Name
Ahmad, Nur Irwany
Alternative Name
Ahmad, Nur Irwany
Main Affiliation
Scopus Author ID
57200991933

Research Output

Filters

3 1
3
Reset filters

Settings
Now showing 1 - 3 of 3
  • Publication
    Construction of calixarene-based sensor: Multilayer Langmuir–Schaefer film and first-principles studies for 4-aminobenzoic acid sensing application
    ( 2024-02-01)
    Yeong Yi Wong
    ;
    Faridah L Supian
    ;
    Afiq Radzwan
    ;
    Nur Farah Nadia Abd Karim
    ;
    Farish Armani Hamidon
    ;
    Nur Irwany Ahmad
    Calixarenes, being well-known macrocyclic structures, have attracted considerable interest in the field of nanosensors due to their diverse advantages. 4-Aminobenzoic acid (PABA) was aimed to be detected by both calix[4]arene (C4) and calix[6]arene (C6) in this host-guest investigation. This study investigated the development of C4-PABA and C6-PABA complexes using the Langmuir–Schaefer (LS) method and first-principles density functional theory (DFT). All of the LS films formed were characterised by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), carbon, hydrogen, nitrogen, oxygen elemental analyser (CHNS), ultraviolet-visible spectroscopy (UV-Vis), and Fourier-transform infrared spectroscopy (FTIR). Additionally, this work applied DFT to compute the binding energy and band gap. Morphological and elemental analysis based on the conducted characterisations indicated the incorporation of PABA via lower rims into both C4 and C6. The computed binding energy and band gap validated the experiment's findings that promising reactivity existed between calixarenes and PABA with the formation of stable complexes. The sensing of PABA by both C4 and C6 was proven. In the near future, the outcomes of this research can be applied to drug delivery systems for pharmaceutical and medical purposes.
  • Publication
    Copper doping effect in the back surface field layer of CdTe thin film solar cells
    ( 2024-02-01)
    Nur Irwany Ahmad
    ;
    Kiong T.S.
    ;
    Doroody C.
    ;
    Rahman K.S.
    ;
    Mohd Natashah Norizan
    ;
    Mohd Fairus Ahmad
    ;
    Kar Y.B.
    ;
    Harif M.N.
    ;
    Amin N.
    In this work, the Solar Cell Capacitance Simulator (SCAPS-1D) is employed to evaluate the characteristics of CdTe thin films with ZnTe as the Back Surface Field (BSF) layer and estimate the effective copper doping ratio at both the atomic scale and the device operational response perspective. The electrical characteristics of ZnTe, at varying levels of copper doping, were derived using density functional theory (DFT) by applying the generalized gradient approximation (GGA) and Hubbard U corrections (DFT+U). The performance of ZnTe with different Cu concentrations as a BSF layer was evaluated by analysing the values of four key parameters that are open circuit voltage (VOC), short circuit current density (JSC), fill factor (FF), and conversion efficiency (η). The results indicate that an increase in Cu concentration from 0% to 3%, 6%, 10%, and 12% resulted in a reduction of the energy band gap. Specifically, the energy band gap decreased from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, and 1.88 eV, respectively. Optimal Cu doping promotes the favourable shift in the valence band maxima (VBM) and formation of p + -ZnTe, lowering thermionic emission and improving carrier lifetime, which results in an improved ohmic contact, η = 18.73% for 10% of Cu content. Excessive doping in contrast degraded the overall device performance by forming an unmatched carrier band offset at the front interface with CdS, increasing the acceptor type defect and CdTe compensation rate. Overall, the findings suggest that incorporating a controlled level of Cu, which in this case is around 10%, promotes the efficiency and stability of the proposed CdTe device configuration to a certain extent.
  • Publication
    Effect of Cuâ‚‚Te Back Surface Interfacial Layer on Cadmium Telluride Thin Film Solar Cell Performance from Numerical Analysis
    ( 2023-05-01)
    Harif M.N.
    ;
    Doroody C.
    ;
    Nadzri A.
    ;
    Nisham Rosly H.
    ;
    Nur Irwany Ahmad
    ;
    Isah M.
    ;
    Amin N.
    Even though substantial advances made in the device configuration of the frontal layers of the superstrate cadmium telluride (CdTe) solar cell device have contributed to conversion efficiency, unresolved challenges remain in regard to controlling the self-compensation and minority carrier recombination at the back contact that limits the efficiency. In this study, a SCAPS-1D simulator was used to analyze the loss mechanism and performance limitations due to the band-bending effect upon copper chloride treatment and subsequent Cu2Te layer formation as the back contact buffer layer. The optimal energy bandgap range for the proposed back surface layer of Cu2Te is derived to be in the range of 1.1 eV to 1.3 eV for the maximum conversion efficiency, i.e., around 21.3%. Moreover, the impacts of absorber layer’s carrier concentration with respect to CdTe film thickness, bandgap, and operational temperature are analyzed. The optimized design reveals that the acceptor concentration contributes significantly to the performance of the CdTe devices, including spectral response. Consequently, the optimized thickness of the CdTe absorber layer with a Cu-based back contact is found to be 2.5 µm. Moreover, the effect of temperature ranging from 30 °C to 100 °C as the operating condition of the CdTe thin-film solar cells is addressed, which demonstrates an increasing recombination tread once the device temperature exceeds 60 °C, thus affecting the stability of the solar cells.
      1  14