Metal-halide perovskite solar cells rival the best inorganic solar cells in power conversion efficiency, providing the outlook for efficient, cheap devices. In order for the technology to mature and approach the ideal Shockley-Queissier efficiency, experimental tools are needed to diagnose what processes limit performances, beyond simply measuring electrical characteristics often affected by pa...

In this paper, fabrication and study of electronic properties of Au/methyl-red/Ag surface type Schottky diode by current-voltage (I-V) method has been reported. The I-V characteristics of the Schottky diode showed the good rectifying behavior. The values of ideality factor n and barrier height b of Au/methyl-red/Ag Schottky diode were calculated from the semi-log I-V characteristics and by usin...

A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode sa...

The integration of graphene and other atomically flat, two-dimensional materials has attracted much interest and been materialized very recently. An in-depth understanding of transport mechanisms in such heterostructures is essential. In this study, vertically stacked graphene-based heterostructure transistors were manufactured to elucidate the mechanism of electron injection at the interface. ...

A 32 by 32 array of packaged 100 μm Geiger-mode avalanche photodiodes were tested and characterized. A breakdown voltage of 32 V was measured; at or just above this voltage is where the device should be biased in order to operate in Geiger-mode. The ideal region of the forward biased IV curve resulted in an ideality factor of 1.0 and no recombination/generation region. In addition, IDL code was...

The temperature-dependent direct current dc characteristics and radio frequency performance of an InGaP/GaAs heterojunction bipolar transistor with the composite passivations on base surface are studied and demonstrated. For comparison, the characteristics of other samples with different treatments on the base surfaces are also included in this work. The device with composite passivations, i.e....

We report the current-voltage behavior for nanoscale point contacts to Si(111) obtained in ultrahigh vacuum using scanning tunneling microscopy. Epitaxial CoSi(2) islands provide single-crystal contacts with well-defined size and shape. The zero bias conductance is found to be independent of the island size (10(2)-10(4) nm(2)) and shape, but varies strongly with the surface Fermi level position...

We investigate the dissociation equilibrium of H2 in very cool, helium-rich white dwarf atmospheres. We present the solution of the non-ideal chemical equilibrium for the dissociation of molecular hydrogen in a medium of dense helium. We find that at the photosphere of cool white dwarfs of Teff = 4000K, the non-ideality results in an increase of the mole fraction of molecular hydrogen by up to ...