Fabrication Of A-C:B/N-Si Solar Cells With Low Positive Bias By Custom-Made-CVD
Boron doped amorphous carbon (a-C:B) film fabricated on n-type silicon using waste palm oil precursor by low positive bias voltage is presented. The rectifying curve were found for all samples under dark measurement revealed that those samples were p-type semiconductor. The +30 V was found the optimized of the electronic properties with the open circuit voltage (VOC), current density (JSC), fill factor (FF) and efficiency (%) were approximately 0.259034 V, 1.299456 mA/cm 2 , 0.240011, and 0.080788 %, respectively. The conversion efficiency of a-C:B has been improved under the influenced of low positive bias.
P-type properties of micro and nano-structured carbon films from hydrocarbon palm oil in photovoltaic heterojunction solar cell applications
The micro and nano-structured amorphous carbon as p-type films prepared from natural palm oil precursor for heterojunction solar cell were presented. Field-emission scanning electron microscopy (FESEM) revealed the micro and nano structured films had particle size in the range of 382 nm to 689 nm and 28 to 34 nm, respectively. The energy-dispersive spectroscopy (EDS) showed the existing of carbon in micro-structured amorphous carbon film and carbon together with boron in nano-structured amorphous carbon film. Solar simulator analysis results showed an open circuit voltage (VOC), current density (JSC), fill-factor(FF) and conversion efficiency (η) of Au/a-C/n-Si/Au were 264.62 mV, 1.50434 mA/cm2, 0.32632, and 0.130154 %, respectively. Meanwhile, the VOC, JSC, FF and η of Au/a-C:B/n-Si/Au solar cell were 271.25 mV, 14.91723 mA/cm2, 0.33582, and 1.542622 %, respectively. The conversion efficiency was increased as the p-type film was in nanostructure form.
Effect of ion bombardment and hydrogen pressure during deposition on the optical properties of hydrogenated amorphous carbon thin films
Abstract Carbon-based thin films are ideal materials for several state-of-the-art applications, such as protective materials and as active films for organic electronics, medical, optoelectronic devices. In this work, we study in detail the effect of the ion-bombardment and the hydrogen partial pressure during deposition on the optical properties of hydrogenated amorphous carbon (a-C:H) thin films grown onto c-Si substrates by rf magnetron sputtering. The optical properties of the a-C:H films were investigated by phase modulated Spectroscopic Ellipsometry in a wide spectral region from the NIR to the Vis-far UV (0.7–6.5 eV). A dispersion model based on two Tauc-Lorentz oscillators, has been applied for the analysis of the measured of the a-C:H films to describe the π–π* and σ–σ* interband electronic transitions, that can describe accurately the optical properties of all amorphous carbons. The applied Vb influences the bombardment of the growing thin films with Ar ions affecting the content of sp2 and sp3 hybridized carbon bonds in the films. As it was found, the increase of the applied negative voltage reduces the optical transparency of the a-C:H films. Also, the H incorporation has been found to change only the energy position of the σ–σ* transitions. Finally, from the study of the refractive index n(ω = 0 eV) it has been found that the increase of the ion bombardment during the films deposition is correlated to an increase in the films density.