Electrochemical half-reaction-assisted sub-bandgap photon sensing in a graphene hybrid phsotodetector

The photogating effect has been previously utilized to realize ultra-high photoresponsivity in a semiconductor-graphene hybrid photodetector. However, the spectral response of the graphene hybrid photodetector was limited by the bandgap of the incorporated semiconductor, which partially compromised the broadband absorption of graphene. Here, we show that this limitation can be overcome in principle by harnessing the electron-accepting ability of the electrochemical half-reaction. In our new graphene phototransistor, the electrochemical half-reaction serves as an effective reversible electron reservoir to accept the photoexcited hot electron from graphene, which promotes the sub-bandgap photosensitivity in a silver chloride (AgCl)-graphene photodetector. The photoconductive gain of ~ 3 × 109 electrons per photon in the AgCl-graphene hybrid is favored by the long lifetime of photoexcited carriers in the chemically reversible redox couple of AgCl/Ag0, enabling a significant visible light (400–600 nm) responsivity that is far beyond the band-edge absorption of AgCl. This work not only presents a new strategy to achieve an electrically tunable sub-bandgap photoresponse in semiconductor-graphene heterostructures but also provides opportunities for utilizing the electrochemical half reaction in other two-dimensional systems and optoelectronic devices.published_or_final_versio

Friction and wear behaviour of cp Ti and Ti6Al4V following nitric passivation

International audienc

Quality Assessment and Potential Reuse of Treated Wastewater by Activated Sludge (Sana'a city, Yemen) : Physico-Chemical Study

The Sana'a Basin is located in central highlands of Yemen. This basin is characterized by water crisis due to arid climate with low rainfall (170 mm/year), and drawdown of piezometric levels. Promoting water reuse of treated wastewater for irrigation could mitigate this water crisis. This study assesses the performance of Wastewater Treatment Plant (WWTP) by activated sludge of Sana'a City by analyzing the quality raw and treated wastewater predominantly by domestic sewage. A comparison with Yemen and  international guideline reveals the results of pH, EC and PO4 show that the effluent from SWWTP are in admissible standard limit for irrigation. But, the others parameters such as BOD, COD, NH4, TSS, phenols and heavy metals are very high than the standard values due to the overloaded of SWWTP. The added of facultative ponds can improve the performance of this station. Therefore, the quality of final effluent will be better

Mutations in CFAP43 and CFAP44 cause male infertility and flagellum defects in TrypanosomaTrypanosoma and human.

International audienceSpermatogenesis defects concern millions of men worldwide, yet the vast majority remains undiagnosed. Here we report men with primary infertility due to multiple morphological abnormalities of the sperm flagella with severe disorganization of the sperm axoneme, a microtubule-based structure highly conserved throughout evolution. Whole-exome sequencing was performed on 78 patients allowing the identification of 22 men with bi-allelic mutations in DNAH1 (n = 6), CFAP43 (n = 10), and CFAP44 (n = 6). CRISPR/Cas9 created homozygous CFAP43/44 male mice that were infertile and presented severe flagellar defects confirming the human genetic results. Immunoelectron and stimulated-emission-depletion microscopy performed on CFAP43 and CFAP44 orthologs in $Trypanosoma\ brucei$ evidenced that both proteins are located between the doublet microtubules 5 and 6 and the paraflagellar rod. Overall, we demonstrate that CFAP43 and CFAP44 have a similar structure with a unique axonemal localization and are necessary to produce functional flagella in species ranging from $Trypanosoma$ to human