共查询到20条相似文献,搜索用时 15 毫秒
1.
In this paper, the design of a resonant cavity-enhanced (RCE) Schottky photodetector, based on internal photoemission effect and working at 1.55 μm, is presented. In order to estimate the theoretical quantum efficiency we take the advantage of analytical formulation of the internal photoemission effect (Fowler theory), and its extension for thin films, while for the optical analysis of device a numerical method, based on the transfer matrix method, has been implemented. Finally, we complete our design calculating bandwidth and bandwidth-efficiency product.Our numerical results prove that a quantum efficiency of 0.1% is obtained at resonant wavelength (1.55 μm) with a very thin absorbing metal layer (30 nm). Theoretical values of 100 GHz and 100 MHz were obtained, respectively, for the carrier-transit time limited 3-dB bandwidth and bandwidth-efficiency. The proposed photodetector can work at room temperature and its fabrication is completely compatible with standard silicon technology. 相似文献
2.
3.
We report what is believed to be the first demonstration of an optical parametric oscillator directly pumped by the 1.55-mum output of an erbium-doped fiber laser. The oscillator, based on periodically poled lithium niobate, produced 8-muJ idler output near 3.8 mum at a 500-Hz repetition rate when it was pumped with 100-muJ 60-ns pulses at 1.55 mum . Temperature tuning of the 50-mm-long PPLN crystal gave signal and idler ranges of 2.55 to 2.7 mum and 3.65 to 3.96 mum , respectively, limited by mirror reflectivity. A signal-tuning range of 40 nm was observed for 13.5 nm of pump tuning with a fixed grating period and temperature. The optical parameter oscillator could be operated at low temperature with no sign of photorefractive damage. 相似文献
4.
In this work, the nanocrystalline porous silicon (PS) is prepared through the simple electrochemical etching of n-type Si (1 0 0) under the illumination of a 100 W incandescent white light. SEM, AFM, Raman and PL have been used to characterize the morphological and optical properties of the PS. SEM shows uniformed circular pores with estimated sizes, which range between 100 and 500 nm. AFM shows an increase in its surface roughness (about 6 times compared to c-Si). Raman spectra of the PS show a stronger peak with FWHM=4.3 cm−1 and slight blueshift of 0.5 cm−1 compared to Si. The room temperature photoluminescence (PL) peak corresponding to red emission is observed at 639.5 nm, which is due to the nano-scaled size of silicon through the quantum confinement effect. The size of the Si nanostructures is estimated to be around 7.8 nm from a quantized state effective mass theory. Thermally untreated palladium (Pd) finger contact was deposited on the PS to form MSM photodetector. Pd/PS MSM photodetector shows lower dark (two orders of magnitude) and higher photocurrent compared to a conventional Si device. Interestingly, Pd/PS MSM photodetector exhibits 158 times higher gain compared to the conventional Si device at 2.5 V. 相似文献
5.
《Current Applied Physics》2010,10(3):900-903
The fabrication and characterization of an organic photodetector (OPD) in the form of ITO coated glass/polycarbazole (PCz)/Al Schottky contact is reported. The device has been fabricated in our laboratory for the first time using the polymer synthesized by us. The device has been subsequently characterized in respect of electrical and optical properties in order to explore its potential for possible use as a detector in the visible region at 650 nm. It is observed that the detector exhibits a reasonably high value of peak detectivity (∼6 × 106 cm Hz1/2 W−1) near zero bias voltage at V = 0.2 V. 相似文献
6.
提出了一种减小GaN肖特基结构紫外探测器暗电流的方法.该方法是在普通的GaN肖特基结构的表面增加一层薄的p-GaN.模拟计算结果表明,该层p-GaN能增加肖特基势垒高度,从而减小了器件的暗电流,提高了器件性能.进一步的计算还发现,对于p型载流子浓度较高的情况下,只需要很薄的一层p-GaN就能显著增加肖特基势垒高度,对于p型载流子浓度较低的情况下,则需要较厚的一层p-GaN才能有较好的肖特基势垒高度增加效果.
关键词:
GaN
肖特基结构
紫外探测器
暗电流 相似文献
7.
The theoretical optimization of the design parametersN
A
,N
D
andW
P
has been done for efficient operation of Au-p-n Si solar cell including thermionic field emission, dependence of lifetime and mobility on impurity concentrations, dependence
of absorption coefficient on wavelength, variation of barrier height and hence the optimum thickness ofp region with illumination. The optimized design parametersN
D
=5×1020 m−3,N
A
=3×1024 m−3 andW
P
=11.8 nm yield efficiencyη=17.1% (AM0) andη=19.6% (AM1). These are reduced to 14.9% and 17.1% respectively if the metal layer series resistance and transmittance with
ZnS antireflection coating are included. A practical value ofW
P
=97.0 nm gives an efficiency of 12.2% (AM1). 相似文献
8.
Breakdown characteristics of AIGaN/GaN Schottky barrier diodes fabricated on a silicon substrate 下载免费PDF全文
In this work, the breakdown characteristics of AlGaN/GaN planar Schottky barrier diodes (SBDs) fabricated on the silicon substrate are investigated. The breakdown voltage (BV) of the SBDs first increases as a function of the anodeto-cathode distance and then tends to saturate at larger inter-electrode spacing. The saturation behavior of the BV is likely caused by the vertical breakdown through the intrinsic GaN buffer layer on silicon, which is supported by the post-breakdown primary leakage path analysis with the emission microscopy. Surface passivation and field plate termination are found effective to suppress the leakage current and enhance the BV of the SBDs. A high BV of 601 V is obtained with a low on-resistance of 3.15 mΩ·cm^2. 相似文献
9.
Breakdown characteristics of AlGaN/GaN Schottky barrier diodes fabricated on a silicon substrate 下载免费PDF全文
In this work, the breakdown characteristics of AlGaN/GaN planar Schottky barrier diodes(SBDs) fabricated on the silicon substrate are investigated. The breakdown voltage(BV) of the SBDs first increases as a function of the anodeto-cathode distance and then tends to saturate at larger inter-electrode spacing. The saturation behavior of the BV is likely caused by the vertical breakdown through the intrinsic GaN buffer layer on silicon, which is supported by the postbreakdown primary leakage path analysis with the emission microscopy. Surface passivation and field plate termination are found effective to suppress the leakage current and enhance the BV of the SBDs. A high BV of 601 V is obtained with a low on-resistance of 3.15 mΩ·cm2. 相似文献
10.
The Schottky barrier heights for Au, Al, and Ba on diamond are reported. The variation of the barrier energy with metals is found to be small. A previously incorrect report of S for SiC is corrected. 相似文献
11.
4H-SiC Schottky barrier diodes with semi-insulating polycrystalline silicon field plate termination 下载免费PDF全文
Based on the theoretical analysis of the 4H-SiC Schottky-barrier diodes(SBDs) with field plate termination, 4H-SiC SBD with semi-insulating polycrystalline silicon(SIPOS) FP termination has been fabricated. The relative dielectric constant of the SIPOS dielectric first used in 4H-SiC devices is 10.4, which is much higher than that of the SiO2dielectric,leading to benefitting the performance of devices. The breakdown voltage of the fabricated SBD could reach 1200 V at leakage current 20 μA, about 70% of the theoretical breakdown voltage. Meanwhile, both of the simulation and experimental results show that the length of the SIPOS FP termination is an important factor for structure design. 相似文献
12.
G. A. Adegboyega A. Poggi E. Susi A. Castaldini A. Cavallini 《Applied Physics A: Materials Science & Processing》1989,48(4):391-395
A wet chemical etch preceding the usual cleaning process has been found to yield Schottky barriers of high values on p-type silicon. This procedure produces a passivated surface layer which has resulted in Al/0-Si Schottky diodes with barrier height of 0.75 eV and ideality factor of 1.15. Measurements have confirmed the presence of electrically active donor-like states in this surface layer. The origin of the donor states is explained in terms of the deactivation of the boron acceptor by the formation ofH
+
B
– pairs. 相似文献
13.
Commercial grating-tuned single-mode extended-cavity semiconductor lasers (ECLDs) can be tuned over 100 nm near 1.55mum . This continuous tuning with no mode hopping requires delicate factory adjustments and high mechanical stability so that the wavelength precision is kept as high as possible and the mismatch between the lasing wavelength and the wavelength of minimum loss remains as small as possible. The addition of a photorefractive crystal inside the cavity creates an adaptive spectral filter that decreases the loss of the lasing mode and thus enhances its stability. For what is to our knowledge the first time, we demonstrate the extension of the available wavelength-mismatch range without mode hopping by the addition of a CdTe photorefractive crystal inside the cavity of a single-mode grating-tuned ECLD. 相似文献
14.
15.
A comparative study is performed of Schottky barrier structures based on Si and GaAs as photoelements and detectors of electrons with energies of 40 and 60 keV. It is shown that introduction of a dielectric interlayer between the metal and semiconductor 1.5–3 nm thick permits increase in ic and Vx of the structures in both the photodetector and electron count regimes. A complex temperature dependence of structure properties in the electron count regime was found, depending on barrier metal thickness and electron energy.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 76–81, April, 1991. 相似文献
16.
17.
Effect of temperature on photoresponse properties of solar-blind Schottky barrier diode photodetector based on single crystal Ga_2O_3 下载免费PDF全文
《中国物理 B》2019,(4)
A solar-blind photodetector is fabricated on single crystal Ga_2O_3 based on vertical structure Schottky barrier diode. A Cu Schottky contact electrode is prepared in a honeycomb porous structure to increase the ultraviolet(UV) transmittance.The quantum efficiency is about 400% at 42 V. The Ga_2O_3 photodetector shows a sharp cutoff wavelength at 259 nm with high solar-blind/visible(= 3213) and solar-blind/UV(= 834) rejection ratio. Time-resolved photoresponse of the photodetector is investigated at 253-nm illumination from room temperature(RT) to 85.8℃. The photodetector maintains a high reversibility and response speed, even at high temperatures. 相似文献
18.
The results obtained in our previous work [4] are revised taking into account the dependence of the electron affinity on the polytype of silicon carbide SiC. The dependence of the energy level of vacancies in a polytype of silicon carbide on the band gap is determined from the data on the Schottky barrier height and is explained in the framework of a simple two-band model. 相似文献
19.
20.
The Schottky photodetector was fabricated on GaN epilayers grown by
metalorganic chemical vapour deposition (MOCVD). The spectral response of the
Schottky photodetector was characterized. A new model is proposed to
interpret the characteristic of the spectral response curve of the Schottky
photodetectors by introducing a penetrating distance of an incident light at
a certain wavelength in the current continuity equation and the interface
recombination at the metal--semiconductor rectifying contact. The expressions
for the spectral response of the Schottky photodetector are deduced and used
successfully to fit the experimental data. 相似文献