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.
Theory of dopant pairs in four-fold coordinated amorphous semiconductors
Abstract The position of energy levels belonging to dopant pairs was investigated in substitutionally p- or n-type doped four-fold coordinated amorphous carbon and silicon by means of Hartree–Fock ab initio and the Fragment Self-Consistent Field method. Our models contain 45 to 583 carbon or silicon atoms. Boron, phosphorus and nitrogen impurities have been incorporated into the amorphous networks. It has been found that the position of midgap states are primarily determined by the separation of the impurity atoms, and the role of the random network is only subordinate. A general relationship is proposed for the determination of midgap energy levels as a function of the distance between dopant pairs investigated for amorphous carbon and silicon.