Itsara Srithanachai

Novel design of solar cell efficiency improvement using an embedded electron accelerator on-chip

In this paper, we propose a novel design of an electron accelerator on-chip by using a small scale device known as a PANDA microring resonator, which can be embedded within the solar cell device, where the trapped electron can be accelerated and moved faster to the final destination. Therefore, the solar cell efficiency can be improved. In principle, a PANDA microring can generate the optical tweezers for hole tapping and transportation. The transported holes can be accelerated and moved via the optical waveguide to the solar cell device contact, where the effect of defects in silicon bulk can be solved. Therefore, this technique can be used to improve the solar cells performance. In practice, the accelerator unit can be embedded within the solar cell device, which allows the trapped holes moving to the required destination. This is claimed to be a novel technique by using a PANDA microring to accelerate the holes for solar cell performance improvement. Finally, this technique is the starting point of using a PANDA microring to enhance the performance of semiconductor device.

Particle Accelerator Using Optical Tweezer for Photodetector Performance Improvement

A photodetector performance improvement technique using a particle accelerator in the modified add-drop optical filter is proposed. An optical tweezer is used to control the electron movement within the device, where an electron (particle) can be accelerated and moved faster than the normal condition, where finally the silicon bulk defects and diode performance degradation can be solved. In simulation, a PANDA microring is configured by a modified add-drop filter that can be used to increase the electron speed. In operation, the trapped electrons in a diode can be trapped, controlled, and transported from anode to cathode contacts. In the design system, the trapping probe can be adjusted to fit the atom size from 200 pm (picometer) to 1.4 nm (nanometer) by controlling the ring parameters. The goal of this paper is to present the use of a PANDA microring for photodetector performance improvement, which can be used for many applications.

An improvement of electrical characteristics of P-N diode by X-ray irradiation method

This paper presents a new technique of semiconductor fabrication technology, where a soft X-ray annealing method is proposed as a new technique and used in this work. The effect of Pt and Soft X-ray annealing on P-N diodes was investigated. The tested P-N diodes were fabricated at TMEC laboratory using CMOS technology. Results obtained have shown that the platinum doping is affected both reverse and forward current characteristics of P-N diode, the leakage current is increased slightly, while the forward current is also increased 3 to 4 times, which is a result of reduction of carrier recombination lifetime of diode from 72 to 55 µs. The characteristics of P-N diode after X-ray irradiation is improved significantly. There is a slight reduction of leakage current, whereas the forward current is increased about 3 to 4 order of magnitude. Furthermore, the recombination lifetime is decreased from 54 to 48 µs.

Improving the forward current of P-N diode using soft X-ray annealing method

This paper presents a new result to improve the performance of P-N diode. The P-N diodes are fabrication using CMOS technology at TMEC. Electrical characteristics of P-N junction diode can be analyzed by current-voltage (I-V) measurement. This paper investigates X-ray irradiation by its electrical characteristics of difference X-ray exposure time. The X-ray energy use to expose 55 and 70 keV various time in the range 5-205 sec of exposure. After X-ray irradiation the forward current are increased about 3-4 orders. The series resistance and recombination lifetime are main factor for describe the change of forward current. Series resistance after X-ray irradiation with 55 and 70 keV are decreased from 10 kΩ to 5 Ω, which show that the device performance of diode are increased after X-ray irradiation. While the recombination lifetime are decreased from 55 to 48 μsec and 52 to 45 μsec at 55 and 70 keV, respectively. From the results show that soft X-ray annealing is very important to semiconductor industry.

Improving Forward Current Characteristics of Diode by X-Ray Irradiation

These papers investigates the effect of X-ray on forward current characteristics of diode. The forward current of diode after X-ray irradiation energy 40 keV at the exposure time ranging 5, 10 second was increased, while 15 and 20 second was decreased. X-ray causes changing of the electrical characteristics of diode. Series resistance is the main factor for analyze on forward current characteristics. From the results, X-ray can improve performance of diode at the exposure time for 5 and 10 second.

Preparation and Properties Indium Tin-Oxide Thin Films by RF Sputtered for Photodetectors

This paper descript studying and preparation indium-tin oxide (ITO) thin film from method 90 wt.% In2O3 and 10 wt.% SnO2 formula target with 99.99% purity on glass slide by RF reactive sputtering method at room temperature. This paper, sputtering time 5, 15, 30 and 60 mins. Thin films ITO were measured crystallization, optical and electrical characteristic by an X-ray diffractometer (XRD), scan electron microscopy (SEM) , Four Point Probe and UV-VIS spectrophotometry. The results found that thin films which made from RF sputtering method had a high crystallization, order arrangement grain. Strong peak of XRD (400) and (441), low resistivity are 2.2 x 10-3, 4.4 x 10-3, 1 x 10-3 and 7 x 10-4 Ω-cm, transmittance are 82%, 84%, 87% and 89%, respectively. The overall experimental results identify that fabricated thin films ITO have good properties and is suitable for transparent electrode application. The ultimate goal is developing schottky photodetector.

Removing the transients electron trapping in P-N junction diode by using soft X-ray annealing method

This paper describes a transient phenomenon in the reverse current of P-N junctions giving rise to a hump at a specific reverse bias. P-N diode as been fabricated by a deep boron ion implantation (120 keV) and a junction depth around 4 μm is expected. Ion implantation can cause defect in silicon substrate even if the device was cured by annealing process, the defect or its effect is still remained. I-V characteristic has been acquired from –10 V to 0 V in temperature variation of 30–80oC. At the specific condition of –3 V, 80oC humps occurred on the curve and when the device was exposed to X-ray at energy of 40, 55 and 70 keV. The humps were then shifted toward 0 V. Activation energy has been calculated in order to give an insight into the device characteristics. It revealed the presence of a non-uniform density of electron traps corresponding to a broad range of energy levels from about 0.65–0.67 eV above the intrinsic band. This report shows an interesting phenomenon of the deep P-N junction diode modified by X-ray irradiation.

The Effect of X-Ray Irradiation on the Electrical Properties of Pt-Doped P-N Diode

This paper presents the effect of X-ray irradiation on the electrical properties of Pt-doped P-N diode with X-ray energy 70 keV for 205 seconds. The results show that the radiation affected both reverse and forward current characteristics of P-N diode. The forward current is increased about 3 orders after radiation, while the leakage current is increased slightly after irradiation. Moreover, build-in voltage value is also changed after irradiation. The cause of parameters changing can be analyzed from carrier lifetime and series resistance. It can be seen clearly that X-ray irradiation technique are significant and can be used to improving electronic devices.

Carrier Lifetime of Platinum Doped P-N Diode after Irradiation by Soft X-Ray

This paper analyzes the effect of X-ray irradiation on the electrical properties of Pt-doped p-n diode. X-ray energy irradiated on Pt-doped P-N diode with 70 keV with time 205 sec. After irradiations, the current-voltage (I-V) characteristics and capacitance-voltage (C-V) characteristics and carrier degeneration lifetime (τg) were investigated. The results show that the leakage current is slightly increased after the diodes were exposed X-ray and affect higher degeneration carrier lifetime. The effects after X-ray irradiation indicated that the defects of the diode have been changed.

Light-Response Characteristics of Platinum Doped Silicon Photodetector

The purposeof this research article is present electrical characteristic of Pt-doped silicon photodetector compare with undoped silicon photodetector. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Pt-doped detector were investigated. In this experiment, the results of Pt-doped detector show that the dark currentisobviously decreased and the photocurrent is decreased about 9 to 10 orders. Furthermore, the capacitance characteristic isslightly increased about 0.15 pF. The effects platinum on silicon indicated the carrier in silicon have been changed.