Effect of p-type transition metal dichalcogenide molybdenum ditelluride (p-MoTe2) layer formation in Cadmium Telluride solar cells from numerical analysis
In this paper, we have investigated the effects of transition metal dichalcogenide namely Molybdenum ditelluride (MoTe2) layer formation in between Cadmium Telluride (CdTe) absorber layer and Mo back contact from numerical modeling. The main purpose was to investigate the possible effects of p-type MoTe2 in CdTe thin film solar cell. Energy band line-up in the vicinity of Mo/MoTe2/CdTe interface is investigated to explain the interface properties in terms of various parameters. It was found that p-type MoTe2 has some effects to the performance of CdTe thin film solar cells. Thickness, bandgap energy and carrier concentration of p-MoTe2 all have been varied in the numerical simulation to observe its effects on the cell performance. It was found that when thickness of MoTe2 is less than 20 nm, the cell efficiency decreases, which may be due to the shunting caused by the thinner p-MoTe2. Furthermore, the increase in MoTe2 bandgap results in unfavorable effect to the performance of the cell mainly due to the possibility of electrons to drift towards the back contact and recombination. The increase of the carrier concentration improves the cell performance. This could be attributed to the less recombination of electrons as well as less built in potential (Vbi) at MoTe2/CdTe junction.
Tellurium depletion electrical effects in MoTe2-x single crystals doped with bromine
Electrical conductivity and thermoelectric power measurements have been performed on n-type MoTe2-single crystals in a wide temperature range (125–770 K). Stoichiometric samples were prepared by vapour transport with bromine as transport reagent. The experimental results which have been performed along a direction perpendicular to the c-axis, are analysed with the model already used for p-type MoTe2-x single crystals grown in a molten tellurium bath without any contaminating reagent. A bromine donor level which is located near the bottom of the conduction band is found and takes into account all the new experimental results. The semiconductor is compensated and the random potential due to the charged lacunar sites and bromine impurities induces a broadening of this level into a narrow band for the compound with the larger tellurium depletion. This band contributes to the conduction in the form of thermally activated hopping. The schematic band structure deduced from transport measurements is in good agreement with the electronic band structure of the group VI transition metal dichalcogenides with trigonal prism coordination.
Fascism in Britain: A History, 1918-1985
Tracing its origins from shortly after the World War I, this book presents a portrait of fascism in the 1930s. It reassesses Mosley's career, describes the reasons for internment in 1940 and the effect it had on leading fascists, exposes the famous Britons who subscribed to fascism, reveals the ominous re-emergence of the tradition after 1945, and explains its remarkable persistence into the l980s.