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.
Deposition of Amorphous Carbon Film Using Natural Palm Oil By Bias Assisted Pyrolysis-CVD For Solar Cell Applications
In this paper, an in‐situ boron doped amorphous carbon (a‐C:B) film deposited by bias assisted pyrolysis‐CVD using natural palm oil as carbon source was reported. The effects of negative bias on the optical band gap, resistivity as well as conductivity and electronic properties of a‐C:B films have been explored by multiple analysis techniques such as UV‐vis spectroscopy, current‐ voltage (I‐V) measurement and solar simulator. We have observed negative bias ‐10 V and ‐20 V reduced the optical transparency and improved electrical properties of a‐C:B films. The optical band gap decreased from 2.3eV (no applied bias) to 2.2eV (with DC bias). The current voltage measurement revealed a rectifying characteristic formed by a‐C:B films and n‐type silicon. Furthermore, the negative bias has improved the electronic properties of a‐C:B film compared with 0 V bias. The open circuit voltage (VOC), current density (JSC), fill factor and efficiency at ‐20 V were 0.426V, 5.351mA/cm2, 0.243, and 0.553 %, respectively.
Photoreflectance characterization of vanadium-doped GaAs layers grown by metalorganic vapor phase epitaxy
Abstract We characterized the vanadium-doped (GaAs:V) layers grown on GaAs substrate by metalorganic vapor phase epitaxy. The conductivity of the samples is checked by the Hall effect measurements, and it is n type with electrons concentration ranging from 2×10 13 to 2×10 17  cm −3 . We used the photoreflectance technique (PR) to study the effect of vanadium doping on the optical properties of GaAs. Our experimental results show that the built-in electric field F and the broadening parameter Γ 0 increase with V-doping concentration. Furthermore, the temperature dependence of the built-in electric field and the broadening parameter of GaAs:V samples have been investigated by PR. It has been observed that these parameters increase with increasing temperature. The decrease of the built-in electric field with decreasing temperature is due to the photovoltage effect.We characterized the vanadium-doped GaAs (GaAs:V) layers grown on GaAs substrate by metalorganic vapor phase epitaxy.