![]() However, little is known as for as few layer MPX 3 materials are concerned and recently, this area has been attracting considerable attention 40, 41, 42 particularly towards catalysis 43, 44, 45, 46, 47 and UV photodetector 48. This class of layered compounds have been wellexplored in the latter half of 20 th century towards understanding their crystal structure and intercalation properties 31, 32, 33, 34, 35, 36, 37, 38, 39. Both TMDs and black phosphorus possess small band gaps thus restricting their applications in optoelectronics using light of short wavelength field effect transistors (FETs) 20, 26.Ĭontinuous search for new 2D-materials has recently led to a well-studied class of bulk layered semiconducting metal phosphotrichalcogenides with formula MPX 3 (M = Ni, Fe, Mn, Co, V, Zn etc X = S and Se). The disadvantage though is its stability that is still being tackled. Recently, phosphorene has been looked at, as a potential candidate for optoelectronic, electronic devices and sensors 26, 27, 28, owing to its high on/off ratio coupled with high carrier mobility 29, 30. Though the TMDs (MoS 2, WSe 2) have shown high on/off ratios with tunable band gap in the visible wavelength range 24, 25, the low carrier mobility is of concern. This has led to various fundamental studies in the areas of electronic, optoelectronic and ultrasensitive sensors with atomically thin MoS 2 membranes 15, 16, 17, 18, 19, 20, 21, 22, 23. Bulk MoS 2 is semiconducting in nature with an indirect band gap of ~1.2–1.4 eV 13, while mono-layer MoS 2 possesses direct band gap of 1.8 eV 14. Transition metal dichalcogenides (TMDs) such as MoS 2 form the next class of well-studied compounds with certain band gap tunability 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. However, the zero band gap of pristine graphene limits its use in optoelectronics and other applications. ![]() ![]() Pulsed hysteresis loops were acquired at room temperature with a Radiant Technologies RT-66A measurement system in order to determine the ferroelectric properties of the PZT layer.Among the 2-dimensional layered materials, graphene has received considerable attention due to its ultrahigh mobility and tunability of layer thickness 1, 2. Transmission electron microscopy showed that the interfaces were sharp and smooth with no significant interdiffusion or formation of secondary phases. Rutherford backscattering data confirmed that the film stochiometry was consistent (within error) with that of the target materials. Analysis by x-ray diffraction, performed before patterning and electrode deposition, indicated that no undesirable phases were formed and that both the LCMO and PZT were well-oriented with strong texture. Platinum electrodes, 1000 Å in thickness, were deposited ex situ after the patterning of the other layers. The ferroelectric layer, PZT, was between 30 Å in thickness. The perovskite semiconductor layer, LCMO, was between 300 to 500 Å thick. Samples were then photolithographically patterned again and ion-milled in order to isolate individual devices. The semiconductor channel and electrodes were patterned with photolithographic wet etch and lift-off techniques, respectively. The ferroelectric layers were patterned by in situ mechanical masking.
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