The roles of amorphous Si nanoparticles in light-emitting diodes (LEDs) based on Er-doped Si(1+x)O(2) films (x representing the degree of Si content, and varying widely from 0 to 4.50) have been investigated. In the aspect of the LEDs' electrical performance, it was found that the incorporation of Si nanoparticles facilitates the electrical conductivity of the films by improving the carrier mobility. With x increasing from 0 to 4.50, the mobility increases monotonically up to 5 times. The efficiency of Er(3+) electroluminescence (EL) at 1.54 µm can be enhanced by as much as 160 times when the degree of Si content x is 2.00, coincident with the value at which the rate of mobility increasing versus x slows down. The fact that the maximum of EL efficiency and the slowing down of the rate of increase of mobility occur at the same x value can be explained by coalescence of Si nanoparticles starting at x = 2.

Optical refractive index (RI) sensors, with the advantages of fast response, resistance to electromagnetic interference, and more options for signal collection, are widely used in biological fields. Compared with the metallic nanoparticle RI sensors based on localized surface plasmon resonance (SPR), nonmetallic nanomaterial RI sensors based on leaky resonant scattering have the advantages of high sensitivity, large sensing volume, good reliability, and more suitability for biosensing. However, so far studies on nonmetallic nanomaterial RI sensors are less reported. In this work, we study semiconductor nanowire (NW) RI sensors using a CdSe nanowire as an example. The NW diameter and substrate effects on the sensitivity of the RI sensors are investigated experimentally and theoretically. The bulk wavelength sensitivity of a suspended NW can be as high as 235 nm/RIU (per refractive index unit), and the highest figure of merit is 4.6. The larger decay length (∼100 nm) of the NW sensor enables greater sensing volume compared with a localized SPR sensor. Besides, we demonstrate that, by choosing proper diameter, we can tune the scattering efficiency peak into the optimum spectral region (600−900 nm) for biosensing. We also demonstrate that the semiconductor NW RI sensors have good reproducibility and reliability. Our work predicts that the semiconductor NW RI sensors have promising applications in diverse sensing devices, especially in biosensing.

Summary Two-dimensional (2D) semi-conductive transition metal dichalcogenides (TMDCs) have shown advantages for logic application. Complementary metal-oxide-semiconductor (CMOS) inverter is an important component in integrated circuits in view of low power consumption. So far, the performance of the reported TMDCs-based CMOS inverters is not satisfactory. Besides, most of the inverters were made of mechanically exfoliated materials, which hinders their reproducible production and large-scale integration in practical application. In this study, we demonstrate a practical approach to fabricate CMOS inverter arrays using large-area p -MoTe 2 and n -MoS 2 , which are grown via chemical vapor deposition method. The current characteristics of the channel materials are balanced by atomic layer depositing Al 2 O 3 . Complete logic swing and clear dynamic switching behavior are observed in the inverters. Especially, ultra-low power consumption of ∼0.37 nW is achieved. Our work paves the way for the application of 2D TMDCs materials in large-scale low-power-consumption logic circuits.

We present a model with which to calculate the index increase induced in standard single-mode fiber by hydrogen loading. Also, we propose that the dominant products of reaction in UV-written hydrogenated standard communication fibers are GeE? and Si-OH. Based on the above models, we calculate the Bragg wavelength shifts that are due to hydrogen diffusion out of the fiber gratings. The relative effective index change that is due to hydrogen dissolved in fiber can be as much as 6 x 10(-4) if standard telecom fiber is hydrogen loaded with a concentration of ~1.44 mol.%. Theoretical results agree with experimental results.