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.
Photoelectrical properties of pulsed laser deposited boron doped p-carbon/n-silicon and phosphorus doped n-carbon/p-silicon heterojunction solar cells
Abstract This paper reports on the successful deposition of boron doped p-type (p-C:B) and phosphorus doped n-type (n-C:P) semiconducting carbon films and fabrication of p-C:B on n-type silicon (Si) substrate (p-C:B/n-Si) and n-C:P/p-Si cells by pulsed laser deposition at room temperature using graphite target. The B and P powder were respectively mixed with graphite powder in range from 1% to 20% of B by weight in the targets (Bwt.%) and 1–10% of P by weight in the targets (Pwt.%), and compressed into pellet targets. The B and P atoms incorporated in the films were determined by X-ray photoelectron spectroscopy to be in the range of 0.2–1.75 and 0.22–1.77 atomic percentages, respectively. The cells performances have been given under illumination I – V rectifying curve (AM 1.5, 100 mW/cm 2 , 25 °C). The open circuit voltage ( V oc ) and short circuit current density ( J sc ) for p-C:B/n-Si are observed to vary from 230 to 250 mV and 1.5 to 2.2 mA/cm 2 , respectively. While, for n-C:P/p-Si cells the V oc and J sc are observed to vary from 215 to 265 mV and 7.5 to 10.5 mA/cm 2 , respectively. The p-C:B/n-Si cells fabricated using 3 Bwt.% shows highest energy conversion efficiency, η  = 0.20% and fill factor, FF = 45%. While, the n-C:P/p-Si cell fabricated using 7 Pwt.% shows highest of η  = 1.14% and fill factor, FF = 41%. The quantum efficiency of p-C:B/n-Si and n-C:P/p-Si cells are observed to improve with percentage of B and P, respectively. The contribution of quantum efficiency in the lower wavelength region (below 750 nm) may be due to the photon absorption by carbon layer and in the higher wavelength region is due to the Si substrates.
Failure analysis for poor solderability of Au surface of PCB
Nonwetting is one of the common problems and is always rejected in electronic assemblies. ENIG pads of a PCBA exhibited nonwetting after lead-free reflow soldering. With the aid of stereomicroscope, SEM&EDS and XRF, a series of analysis was performed. And after visual inspection, surface and cross section analysis, thickness measurement and solderability test, it can be inferred that oxidation of plating surface was the main reason for nonwetting, and corrosion in Ni plating caused an adverse impact on solderalibity.