Controlled synthesis of ultrathin MoS2 nanoflowers is crucial to develop a high-performance room-temperature NO2 gas sensor for the future integration of sensors into smart, portable and Internet-of-Things (IoT)-based devices.
Traps at the (110)Si/SiO2 interface are investigated by combining electrical methods with electron spin resonance (ESR) measurements, and the results are compared to the well studied (100) and (111)Si/SiO2 interfaces. At all three Si crystal faces, the interface trap density Dit as function of energy E in the Si band gap exhibits two peaks at about 0.25 and 0.85 eV above the Si valence band, found to be well correlated with Pb(0) centers (Si3≡Si• defects). By comparing capacitance-voltage (CV) curves at 300 and 77 K of both n- and p-type samples, the Pb(0) defects are confirmed to be amphoteric. Effective passivation of interface traps by H2 annealing suggests that Pb0 defects are responsible for most of interface traps observed in (110)Si/SiO2. The truly amphoteric behavior, implying that one Pb0 defect delivers two interface trap levels, was observed for the (100) and (111)Si faces but not for the (110) face. The estimated interface trap density Nit at the (110)Si/SiO2 interface oxidized at 930 °C is (6.7±0.5)×1012, while the Pb0 density as determined by ESR is about (6±1)×1012 cm−2. Lowering of the oxidation temperature leads to further reduction in the electrically active Pb0 centers fraction at the (110)Si/SiO2 interface.
The influence of a few monolayers of crystalline and amorphous Ge 3 N 4 on the Schottky barrier height of n-type Ge has been investigated. Low temperature capacitance-voltage measurements are used to accurately determine the barrier height. Both amorphous and epitaxial Ge 3 N 4 effectively eliminate pinning of the Fermi level at the metal/Ge interface. Metal/Ge 3 N 4 /n-Ge contacts therefore show a linear dependence of the Schottky barrier height with metal work function. Our results indicate that the Fermi level unpinning is achieved mainly due to the passivation of interface states related to defects at the metal/Ge interface. Aluminum on amorphous and epitaxial Ge 3 N 4 delivers barrier heights of 0.09 6 0.05 and 0.0 6 0.1 eV, respectively, resulting in Ohmic behavior. The formation of epitaxial Ge 3 N 4 requires temperatures above 600 C, whereas amorphous layers can be formed at much lower temperatures. Amorphous Ge 3 N 4 can therefore be used to form Ohmic contacts at a low thermal budget.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.