Fabrication of single crystal diamond capacitive pressure sensor is presented. Firstly, the single crystal diamond cantilever beam was formed on HPHT diamond substrate by using selective high-energy ion implantation, metal patterning, ICP etching and electrochemical etching techniques. Secondly, on this diamond cantilever beam, the desired electrode patterns were processed with photolithography and metal evaporation methods. Furthermore, the displacements of cantilever beam under different pressure conditions were investigated by atomic force microscopy. The capacitance-voltage curves of single crystal diamond cantilever beam and substrate under different force loading conditions were measured by using Agilent B1505A parameter analyzer. The results show that sensitivity increases with the enlargement of electrode area of cantilever beam, and decreases with the rise of measurement frequency.

Diamond microlens arrays with a high occupancy ratio were fabricated by an improved thermal reflow method.

We introduce a simple method with thermal annealing round gold disk for agglomeration to fabricate orderly arranged nanostructure arrays on diamond for single photon source applications. In the annealing process, the dependence of gold sphere size on disk thickness and diameter was investigated, showing that gold sphere diameter was decreased with decreasing gold disk thickness or diameter. The condition parameters of ICP etch were adjusted to obtain different nanostructure morphologies on diamond. The collection efficiency of nitrogen-vacancy (NV) center embedded in nanostructure as-fabricated could reach to 53.56% compared with that of 19.10% in planar case with the same simulation method.

In this study, nitrogen-vacancy center emissions from nanocone structures fabricated on diamond surfaces by gold film annealing and inductively coupled plasma etching techniques were characterized. First, the diamond substate deposited with gold film was annealed to form a nano-sized dot mask. Second, through inductively coupled plasma etching, nanocone-shaped structures were fabricated using optimized gold dots as masks. Finally, the as-fabricated nanocone and planar structures were investigated with photoluminescence experiments at temperatures ranging from room temperature to 80 K, with the results showing approximately two-fold higher emission values for nitrogen-vacancy centers from nanocones.

We report the fabrication of bottom gate a-IGZO TFTs based on HfO₂ stacked dielectrics with decent electrical characteristics and bias stability. The microscopic, electrical, and optical properties of room temperature deposited a-IGZO film with varied oxygen content were explored. In order to suppress the bulk defects in the HfO₂ thin film and hence maximize the quality, surface modification of the SiN_x film was investigated so as to achieve a more uniform layer. The root mean square (RMS) roughness of SiN_x/HfO₂/SiN_x (SHS) stacked dielectrics was only 0.66 nm, which was reduced by 35% compared with HfO₂ single film (1.04 nm). The basic electrical characteristics of SHS-based a-IGZO TFT were as follows: V_th is 2.4 V, μ_sat is 21.1 cm² V⁻¹ s⁻¹, I_on/I_off of 3.3 × 10⁷, I_off is 10⁻¹¹ A, and SS is 0.22 V/dec. Zr-doped HfO₂ could form a more stable surface, which will decrease the bulk defect states so that the stability of device can be improved. It was found that the electrical characteristics were improved after Zr doping, with a V_th of 1.4 V, I_on/I_off of 10⁸, μ_sat of 19.5 cm² V⁻¹ s⁻¹, I_off of 10⁻¹² A, SS of 0.18 V/dec. After positive gate bias stress of 10⁴ s, the ΔV_th was decreased from 0.43 V (without Zr doping) to 0.09 V (with Zr doping), the ΔSS was decreased from 0.19 V/dec to 0.057 V/dec, respectively, which shows a meaningful impact to realize the long-term working stability of TFT devices.

In this study, we obtained a diamond nanocone structure using the thermal annealing method, which was proposed in our previous work. Using finite–difference time–domain (FDTD) simulations, we demonstrate that the extraction efficiencies of nitrogen–vacancy (NV) center emitters in nanostructures are dependent on the geometries of the nanocone/nanopillar, emitter polarizations and axis depths. Our results show that nanocones and nanopillars have advantages in extraction from emitter dipoles with s− and p−polarizations, respectively. In our simulations, the best results of collection efficiency were achieved from the emitter in a nanocone with s−polarization (57.96%) and the emitter in a nanopillar with p−polarization (38.40%). Compared with the nanopillar, the photon extraction efficiency of the emitters in the nanocone is more sensitive to the depth and polarization angle. The coupling differences between emitters and the nanocone/nanopillar are explained by the evolution of photon propagation modes and the internal reflection effects in diamond nanostructures. Our results could have positive impacts on the design and fabrication of NV center−based micro− and nano−optics in the future.