Ahmed Suhail; Genhua Pan; Kamrul Islam; David Jenkins; Angela Milne
Abstract
We demonstrate a high-efficiency graphene/Si Schottky junction solar cell with an easy to fabricate graphene back-contact structure and effective chemical treatments. This device effectively overcame the current challenges associated with reported graphene/Si Schottky solar cell structures. The short-circuit ...
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We demonstrate a high-efficiency graphene/Si Schottky junction solar cell with an easy to fabricate graphene back-contact structure and effective chemical treatments. This device effectively overcame the current challenges associated with reported graphene/Si Schottky solar cell structures. The short-circuit current density for such a device is increased by around 20% due to the increase of the active area of this device, compared to previous graphene/Si Schottky junction solar cell devices. The undesirable s-shaped kink in J-V curves, as found in previous works, have been eliminated by using Formamide treatment for 30 min prior to an annealing process in the forming gas. The fill factor of this device is improved by 40% after this treatment, due to the effective removal of the unwanted PMMA residue. Moreover, volatile oxidant vapour and anti-reflection coating are applied within the fabrication process for this device to further improve solar cell performance. An efficiency of 9.5% has successfully been achieved for the fabricated device using the fabrication techniques developed in this work. Our device presents a viable and achievable approach to preparing low-cost and high-performance graphene/Si Schottky junction solar cells.
M.A. AL-Jalali
Abstract
The S-d exchange interactions in dilute Cu-Mn alloys was studied on concentration (C) varying between 10.5 and 2081.8 ppm of Mn in Cu within the (0.03K–4.2K) temperature range. Using electrical resistivity data on those alloys, the s-d exchange integral (Jsd), which is negative, has calculated ...
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The S-d exchange interactions in dilute Cu-Mn alloys was studied on concentration (C) varying between 10.5 and 2081.8 ppm of Mn in Cu within the (0.03K–4.2K) temperature range. Using electrical resistivity data on those alloys, the s-d exchange integral (Jsd), which is negative, has calculated to show a clear dependence on (Ln C). This dependence, confirming thus the dominance of Kondo effect below 1000 ppm impurity concentration, but above this concentration, we expected an interference between Kondo effect and spin glass regime, which mean that spin glass regime has to prevail more than Kondo effect.
