Chemical modification and vertical stacking of two-dimensional materials are promising techniques for new nanoelectronic devices. We present Density Functional Tight Binding(DFTB) calculations of a field-effect device...Chemical modification and vertical stacking of two-dimensional materials are promising techniques for new nanoelectronic devices. We present Density Functional Tight Binding(DFTB) calculations of a field-effect device,based on lateral and vertical heterostructures of 2D materials. The device consists of a phosphorene channel protected by graphene sheets, which work as contacts and are divided into the source and drain by local hydrogenation of graphene, which gives insulating graphane. In this device composed of only 3 layers, single sheets of graphene-graphane can work as both leads and oxide gate, while also acting as protective layers for a phosphorene channel. We show how for perfect vd W heterostructures of graphane/phosphorene/graphane and graphene/phosphorene/graphene the Schottky barrier is deeply influenced by normal electric fields, and we characterize electronic transport of such a device. Finally, we characterize phosphorene channel doping and defects, which, at very high densities in the transport direction, enables transport inside the phosphorene bandgap.展开更多
Tio2(001) surface of rutile TiO2 single crystals was studied by surface photovoltage spectrum (SPS) and electrical field-induced surface photovoltage spectrum (EFISPS)techni(lue. The two SPS responses peak at 360 nm a...Tio2(001) surface of rutile TiO2 single crystals was studied by surface photovoltage spectrum (SPS) and electrical field-induced surface photovoltage spectrum (EFISPS)techni(lue. The two SPS responses peak at 360 nm and 410 nm were identified as direct transition and indirect transition of TiO2(001) plane, respectively. And it was found that the indirect transition of TiO2 was very sensitive to the external electrical field. These results indicate that SPS and EFlSPS are effective means to study the opto-electrical characteristics ofsemico nd uctors.展开更多
基金supported through the German Research Foundation within the project “Straintronics of imperfect quasi-two-dimensional materials: coplanar vs lamellar heterostructures” (CU 44/43).
文摘Chemical modification and vertical stacking of two-dimensional materials are promising techniques for new nanoelectronic devices. We present Density Functional Tight Binding(DFTB) calculations of a field-effect device,based on lateral and vertical heterostructures of 2D materials. The device consists of a phosphorene channel protected by graphene sheets, which work as contacts and are divided into the source and drain by local hydrogenation of graphene, which gives insulating graphane. In this device composed of only 3 layers, single sheets of graphene-graphane can work as both leads and oxide gate, while also acting as protective layers for a phosphorene channel. We show how for perfect vd W heterostructures of graphane/phosphorene/graphane and graphene/phosphorene/graphene the Schottky barrier is deeply influenced by normal electric fields, and we characterize electronic transport of such a device. Finally, we characterize phosphorene channel doping and defects, which, at very high densities in the transport direction, enables transport inside the phosphorene bandgap.
文摘Tio2(001) surface of rutile TiO2 single crystals was studied by surface photovoltage spectrum (SPS) and electrical field-induced surface photovoltage spectrum (EFISPS)techni(lue. The two SPS responses peak at 360 nm and 410 nm were identified as direct transition and indirect transition of TiO2(001) plane, respectively. And it was found that the indirect transition of TiO2 was very sensitive to the external electrical field. These results indicate that SPS and EFlSPS are effective means to study the opto-electrical characteristics ofsemico nd uctors.
