The optically active carbon related G‐center is attracting great interest because of evidence that it can provide lasing in silicon. Here a technique to form the G‐center in silicon is reported. The ...carbon G‐center is generated by implantation of carbon followed by proton irradiation. Photoluminescence measurements confirm the controlled formation of high levels of the G‐center that, importantly, completely dominates the emission spectrum. Unlike previous methods of introducing the G‐center the current approach significantly is truly fully compatible with standard silicon ULSI (ultralarge scale integration) technology.
The optically active carbon related G‐center can provide lasing in silicon. A technique to form the G‐center that, unlike previous methods, is fully compatible with standard silicon device technology is reported. It is generated by implantation of carbon followed by proton irradiation. Photoluminescence measurements confirm the controlled formation of high levels of the G‐center, which completely dominates the emission spectrum.
Kretschmann-based surface plasmon resonance (K-SPR) is suitable for biomolecular sensing which provides label-free and quick detection results with real-time analysis. In this work, we have ...investigated the effect of graphene oxide (GO) with titanium dioxide (TiO
2
) thin films that are placed in hybrid above metal layers such as gold (Au), silver (Ag) and copper (Cu) with the presence of chromium (Cr) as an adhesive layer. The thickness of the Au, Ag and Cu metal thin films were optimized to 40, 30 and 30 nm, respectively, with a fixed thickness of GO of 2 nm and TiO
2
of 1.9 nm. The sensing was evaluated for SPR excitation at three different visible wavelengths of 633, 670 and 785 nm. The performance of sensing was analyzed based on the reflectance intensity and full-width at half-maximum (FWHM) of the spectrum using the finite-difference time-domain (FDTD) method. The sensitivity was calculated for analyte sensing in dielectric mediums of air versus water. The sensitivity increment percentage (%Δ
S
) was determined when comparing analyte detection using Cr/metal and Cr/metal/GO/TiO
2
sensor structures. The highest sensitivity of 94.51 deg/RIU was achieved for Cr/Cu/GO/TiO
2
K-SPR sensor at 633 nm wavelength.
The effect of the temperature ranging from cryogenics to room temperature were investigated on the formation of the optically-active point defect called the G-centre. The G- centre as an emissive ...point defect gained a lot of attention recently due to its sharp zero phonon luminescence peak at a wavelength of 1.28 μm (0.97 eV) with the evidence of lasing occurred in the structure. The emission of the G-centre is attributed to the carbon substitutional-carbon interstitial (CsCi) complex which interacts with silicon interstitials during the damage event. This complex is generated by implantation of carbon and followed by proton irradiation. Prior to the carbon implantation, two of the samples were pre-amorphised by germanium. Photoluminescence (PL) measurements were carried out at temperature ranging from 80 K up to room temperature to observe the intensity of the main peaks. The results confirm that the main peaks of point-defect centre in all of the samples including the G-centre suffer from the temperature quenching. However, the peak intensity for some of the wavelength especially the ones with high FWHM, do perform better at high temperature. The temperature quenching phenomena observed in the point-defect technique is the main problem that needs to be addressed and solved before realizing the method in the all silicon photonic system.
Silicon photonics technology is on its last hurdle to complete the system with active research on enhancing the light extraction efficiency of silicon. Silicon has a very poor radiative emission ...efficiency due to its indirect bandgap, thus making the probability of radiative recombination to be very low. The periodic quantum confinement structures such as photonic crystals (PhCs) can be tailored to increase the radiative recombination probability at the desired wavelengths. In this paper, we have optimized the silicon photonic crystal (Si PhCs) parameters to obtain luminescence at silicon bandgap and telecommunication wavelength using FDTD method. The extraction of photons is mostly conquered in the silicon structure that has lattice constant, a: 480 nm with radius, r: 140 nm and a: 500 nm with r: 160 nm. We have also observed the emissive photon luminescence that emerges in the most stable state of optical communication wavelength at 1310 nm.
Diabetes mellitus is a disease of metabolic disorders where human blood contains a high amount of sugar level for a prolonged period. This study aims to simulate how effective sensor based on MRR and ...SPR for the purpose of diabetes monitoring. The results show that sensor based on MRR and SPR provides the ability to detect low level of glucose concentration as low as 7 mmol/L (0.13%) and the ability to detect resonance shift for very small glucose concentration change. Therefore, the sensor based on MRR and SPR can be used for diabetes monitoring. The sensitivity of the sensor based on MRR and SPR is 85.84 nm/RIU and 116.69 °/RIU respectively. These findings are important for the development of diabetes monitoring based on MRR or SPR.
Silicon photonics has gained more popularity in the last decade stimulated by a series of recent breakthroughs and attractive potential applications in the integrated-optics. One of the great ...challenges is to modify the silicon lattice so as to enhance the light emission properties. Moreover, by referring to Moore’s Law, there are concerns of the increase in interconnect time delay which can surpass the switching time if the gate length in transistors are continued to scale down. By implementing the silicon optical emitter on the integrated circuit, it will eliminate this major problem thus enhancing the performance and speed of the computer. This work will focus on researching the point defect especially the G-centre in silicon as a potential technique to emit coherent light from silicon. We have investigated and presented a new approach to incorporate high levels of the emissive G-centre peaking sharply at 1280 nm by implanting carbon and protons into the silicon lattice. Significantly this technique utilizes fully ULSI technology compatible processes such as ion implantation and high temperature annealing. Rutherford backscattering spectrometry (RBS) and transmission electron microscopy (TEM) techniques were used along with the photoluminescence measurement to correlate the optical and structural properties of the G-centre formed by the carbon implantation and high energy ion irradiation. The analysis reveals that the silicon interstitials generated after proton irradiation are an essential factor in forming the G-centre complex. We have also introduced the dislocation engineering technique into the silicon lattice with the G-centre complexes. The results are promising and with optimization of the technique to introduce the dislocation loops into the G-centre technique, the temperature quenching problem often related to the optically active point-defect centre, may be solved. Electroluminescence (EL) measurements were carried out after the fabrication of the LED devices. Results from the sample with the G-centre luminescence is the most crucial as it shows that by using the proposed technique in this research, luminescence from silicon is indeed possible when electrically pumped. This is an essential key result for the future research of the optically active point-defect especially the G-centre towards the possibility of an electrically pumped, efficient silicon laser.
We report the improvement in silicon band-edge emission when defects are deliberately introduced in the lattice structures. Silicon is a poor light-emitter due to its indirect bandgap nature. This ...paper aims to increase the intensity of the light emission from silicon by implantation of boron which will lead to the formation of dislocation loops between the lattice structures. Prior to that, the silicon samples were implanted with high concentration of carbon. Photoluminescence (PL) measurements were carried out to observe the emission in silicon at near infrared region. The temperatures were varied from 10K to 100K to study the effect of temperature towards the peak luminescence intensity. By observing the PL spectra, there are two main peaks that can be seen at ~1112 nm and 1170 nm. Both peaks show significantly higher intensities in the samples incorporated with boron.
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