A numerical simulation and analysis was performed to investigate the effect of absorber and buffer layer band gap grading and on a Copper-Indium-Gallium-Diselenide (CIGS) solar cell. The software used is the Solar Cell Capacitance Simulator (SCAPS). The absorber and buffer layer energy band structures’ effect on the cell’s output parameters such as open circuit voltage, short circuit current density, fill factor and efficiency were extensively simulated. Two structures of the energy band gap were simulated and studied for each of the absorber and buffer layer. The simulation was done on the uniform structure in which the energy band gap is constant throughout the layer. It was then continued on the cell with graded band structure, where the energy band gap of the material is varied throughout the layer. It was found that the cell with graded band structure in absorber and buffer layer had demonstrated higher efficiency and better performance in comparison with the cell with uniform band gap structure.
Kertas ini membentangkan kesan dua teknik pengaktifan bermangkin yang berbeza terhadap prestasi terma bagi penyebar haba cip balikan. Penyaduran nikel tanpa elektrik digunakan sebagai salah satu teknik saduran kerana ia boleh membentuk satu lapisan nikel yang ketebalannya seragam ke atas substrat kuprum. Proses pengaktifan bermangkin perlu dilakukan dahulu untuk mengenapkan sesetengah atom nikel ke atas substrat kuprum, supaya enapan nikel mampu untuk memangkinkan proses penurunan yang seterusnya. Dua jenis teknik pengakitfan telah dikaji, iaitu pemulaan galvani dan penyaduran nipis nikel-kuprum. Ujian simpanan suhu tinggi telah dijalankan untuk mengkaji takat resapan antara logam bagi lapisan nikel and kuprum. Kemeresapan terma bagi penyebar haba telah dikaji dengan menggunakan peralatan Nano-flash. Keputusan yang diperolehi menunjukkan bahawa penyebar haba yang diproses dengan penyaduran nipis nikel-kuprum mempunyai nilai kemeresapan terma (35-65 mm2 s-1) yang lebih rendah berbanding dengan penyebar haba yang diproses dengan teknik pemulaan galvani (60-85 mm2 s-1). Selain daripada itu, kajian ini juga menemui ketebalan lapisan antara logam nikel-kuprum dalam penyebar haba ini bertambah daripada 0.2 μm pada keadaan asal kepada 0.55 μm selepas 168 jam simpanan suhu tinggi. Lapisan antara logam nikel-kuprum mempunyai kekonduksian terma yang lebih rendah berbanding dengan kuprum tulen, ini telah merendahkan kemeresapan terma bagi penyebar haba. Kesimpulannya, teknik pemulaan galvani meyediakan prestasi terma yang lebih baik untuk penyebar haba yang digunakan dalam pembungkusan semikonduktor.
The fabrication and characterization of transparent conductors based on single walled carbon nanotube (SWCNT) thin films were carried out in controlled environment and its performance compared. Here, we demonstrate the fabrication of thin, transparent, optically homogeneous, electrically conducting films of metallic enriched single-walled carbon nanotubes via three different deposition techniques namely dip coating, vacuum filtration and Langmuir Blodgett. Optical characterization showed that the maximum transmittance, TM, in Vis region is ~ 96.3% and minimum surface roughness, Ra ~ 4.87 nm achieved via Langmuir-Blodgett technique. I-V characteristics shows minimum sheet resistance, Rs ~ 3.62 × 103 Ω/sq and maximum conductivity, σ ~ 27.65 Ω-1cm-1 for vacuum filtration technique. It is shown that SWCNT deposition technique significantly affects the optical and electrical characteristics of resulting thin films. Langmuir Blodgett method produced film with the lowest surface roughness of Ra ~ 4.87 nm and uniform conductivity of σ ~ 0.025 Ω-1cm-1, whereas vacuum filtration method produced film with the highest surface roughness of Ra ~ 12.83 nm and non-uniform conductivity, σ, ranging from ~ 0.199 to ~0.017 Ω-1cm-1 depending on the film dimensions.