Heterojunction solar cells have potential for very high device voltages and currents, yet this relies on correct preparation of wafer surfaces prior to a-Si deposition. This paper investigates the preparation of wafer surfaces by NaOH texturing prior to amorphous silicon intrinsic layer deposition. It is found that with a CP etch or low temperature anneal after texturing, and with correct depos...

A novel organic-inorganic hybrid layered perovskite-type compound of the general formula A2BX4, bis(IBA)tetrabromolead(II) (1, IBA = isobutyl-ammonium cation), has been successfully synthesized and grown as flake-like crystals, and undergoes two reversible solid-state phase transitions at 315 K and 250 K, and has been systematically characterized using differential scanning calorimetry measurem...

The use of biodegradable material such as simple carbohydrates and recyclable material such as thermo-sensitive polymers is in need to develop a sustainable aqueous two-phase system (ATPS) for the purification of biomolecules. Accurate determination of sucrose concentration is important in liquid-liquid equilibrium (LLE) study of carbohydrate-based ATPS. The well-established phenol-sulfuric aci...

Graphene is an ideal candidate for next generation applications as a transparent electrode for electronics on plastic due to its flexibility and the conservation of electrical properties upon deformation. More importantly, its field-effect tunable carrier density, high mobility and saturation velocity make it an appealing choice as a channel material for field-effect transistors (FETs) for seve...

In this work we study aluminium laser-fired contacts for intrinsic amorphous silicon layers deposited by Hot-Wire CVD. This structure could be used as an alternative low temperature back contact for rear passivated heterojunction solar cells. An infrared Nd:YAG laser (1064 nm) has been used to locally fire the aluminium through the thin amorphous silicon layers. Under optimized laser firing par...

2014 By means of a resistance thermometer structure diffused into the surface of a silicon wafer the temperature has been found to increase within a minute to over 100°C in a CF4 plasma. In contrast the system temperature rises only about 5 °C in the same time. This applies to a system in the tunnel configuration. In a parallel plate system the rise is far less steep and even within the usual e...

The Kubo formula for the electrical conductivity of per stratum of few-layer graphene, up to five, is analytically calculated in both simple and Bernal structures within the tight-binding Hamiltonian model and Green's function technique, compared with the single-layer one. The results show that, by increasing the layers of the graphene as well as the interlayer hopping of the nonhybridized p z ...

We demonstrate germanium photodetectors integrated on submicron silicon waveguides fabricated with a low temperature ( 0.4 A/W and an estimated quantum efficiency of above 90%.

This paper presents magnetic properties of highly ordered ultrathin FeRh films deposited on Si/SiO wafers with MgO as a buffer layer. The antiferromagnetic to ferromagnetic (FM) transition is observed with a thickness as low as 3 nm. However, as the thickness decreases, the residual magnetization (Mrs) at low temperature increases and the amplitude of the transition decreases. In addition, the ...

Graphene field effect transistors commonly comprise graphene flakes lying on SiO(2) surfaces. The gate-voltage dependent conductance shows hysteresis depending on the gate sweeping rate/range. It is shown here that the transistors exhibit two different kinds of hysteresis in their electrical characteristics. Charge transfer causes a positive shift in the gate voltage of the minimum conductance,...