We report the effects of potassium doping on the conductance of individual semiconducting single-walled carbon nanotube ropes. We are able to control the level of doping by reversibly intercalating and deintercalating potassium. Potassium doping changes the carriers in the ropes from holes to electrons. Typical values for the carrier density are found to be ;100–1000 electrons/mm. The effective...

We report the significant improvement of the ferroelectric properties of BiFeO3thin film through control of electrical leakage by Nb doping. A very large remanent electrical polarization value of 80 μC/cm2 was observed in Bi0.8La0.2Nb0.01Fe0.99O3 thin film on Pt/Ti/SiO2/Si substrate. The doping effect of Nb in reducing the movable charge density due to oxygen vacancies in BiFeO3 was confirmed b...

Doping studies have been carried out as a function of silane input fraction over the entire dopant range of silicon in GaAs. In the lower dopant region where the incorporation varies linearly with the silane input mole fraction, the compensation ratio N~/N~ appears to have a constant value of 0.3. In this region the incorporation also is orientation dependent. For SiH 4 input mole fractions hig...

We present a new way to tune the electron-phonon coupling (EPC) in graphene by changing the deformation potential with electron/hole doping. We show the EPC for highest optical branch at the high symmetry point K acquires a strong dependency on the doping level due to electron-electron correlation not accounted in mean-field approaches. Such a dependency influences the dispersion (with respect ...

Nanocrystalline cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I) form an exciting new class of semiconductor materials showing quantum confinement. The emission color can be tuned over the full visible spectral region making them promising for light‒emitting applications. Further control over the optical and magnetic properties of quantum dots (QDs) can be achieved through doping of t...

Graphene, a new material for the electron-device community, has many extraordinary properties. Especially, it provides a perfect platform to explore the unique electronic property in absolutely two-dimensions. However, most electronic applications are handicapped by the absence of a semiconducting gap in pristine graphene. To control the semiconducting properties of graphene, doping is regarded...

Using micro-Raman spectroscopy and scanning tunneling microscopy, we study the relationship between structural distortion and electrical hole doping of graphene on a silicon dioxide substrate. The observed upshift of the Raman G band represents charge doping and not compressive strain. Two independent factors control the doping: (1) the degree of graphene coupling to the substrate and (2) expos...

Solar cell concepts like the IBC concept based on locally doped areas promise a high efficiency of more than 24%. This, however, imposes two major challenges: the capability to create these locally doped regions and – which is often forgotten – the capability to check the actual electronic quality of these sometimes microscopic regions (doping level etc.). In order to keep manufacturing costs s...