Observation of room-temperature resonant photoluminescence in porous silicon

2006 ◽  
Vol 35 (1) ◽  
pp. 151-156 ◽  
Author(s):  
A Kanjilal ◽  
M Song ◽  
K Furuya ◽  
B Mallik
Keyword(s):  
Porous Silicon ◽  
Room Temperature

Room-temperature electroluminescence from erbium-doped porous silicon

1999 ◽  
Vol 75 (25) ◽  
pp. 3989-3991 ◽  
Author(s):  
Herman A. Lopez ◽  
Philippe M. Fauchet
Keyword(s):  
Porous Silicon ◽  
Room Temperature ◽  
Erbium Doped

Room‐temperature backbond oxidation of the porous silicon surface by oxygen radical irradiation

1995 ◽  
Vol 66 (7) ◽  
pp. 836-838 ◽  
Author(s):  
Patrick O’Keeffe ◽  
Yoshinobu Aoyagi ◽  
Shuji Komuro ◽  
Takashi Kato ◽  
Takitaro Morikawa
Keyword(s):  
Porous Silicon ◽  
Silicon Surface ◽  
Room Temperature ◽  
Oxygen Radical ◽  
Porous Silicon Surface

Effect of current density on the porous silicon preparation as gas sensors**

2021 ◽  
Vol 30 (1) ◽  
pp. 257-264
Author(s):  
Muna H. Kareem ◽  
Adi M. Abdul Hussein ◽  
Haitham Talib Hussein
Keyword(s):  
Porous Silicon ◽  
Gas Sensors ◽  
Current Density ◽  
Room Temperature ◽  
Low Cost ◽  
High Surface ◽  
Volume Ratio ◽  
Etching Time ◽  
Force Microscopy ◽  
Materials Used

Abstract In this study, porous silicon (PSi) was used to manufacture gas sensors for acetone and ethanol. Samples of PSi were successfully prepared by photoelectrochemical etching and applied as an acetone and ethanol gas sensor at room temperature at various current densities J= 12, 24 and 30 mA/cm2 with an etching time of 10 min and hydrofluoric acid concentration of 40%. Well-ordered n-type PSi (100) was carefully studied for its chemical composition, surface structure and bond configuration of the surface via X-ray diffraction, atomic force microscopy, Fourier transform infrared spectroscopy and photoluminescence tests. Results showed that the best sensitivity of PSi was to acetone gas than to ethanol under the same conditions at an etching current density of 30 mA/cm2, reaching about 2.413 at a concentration of 500 parts per million. The PSi layers served as low-cost and high-quality acetone gas sensors. Thus, PSi can be used to replace expensive materials used in gas sensors that function at low temperatures, including room temperature. The material has an exceptionally high surface-to-volume ratio (increasing surface area) and demonstrates ease of fabrication and compatibility with manufacturing processes of silicon microelectronics.

Fabrication of Macroporous Silicon in Organic Electrolytes and their Luminescence

2017 ◽  
Vol 748 ◽  
pp. 127-131 ◽  
Author(s):  
Wu Lin Li ◽  
Wen Jing Yang ◽  
Mei Long ◽  
Gen Rong Li ◽  
Yan Ma ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Room Temperature ◽  
Electrochemical Process ◽  
Macroporous Silicon ◽  
Organic Solution ◽  
Organic Electrolytes ◽  
Red Luminescence ◽  
Organic Solutions ◽  
Side Illumination ◽  
Nanoporous Layer

The quasi-regular arrangements porous silicon was fabricated by by electrochemical process using organic solutions with front-side illumination, and SEM showed that the morphology of porous silicon was dependent sensitively on the current density, organic electrolytes and their concentration. The results indicate that N-dimethylformamide (DMF) is the best organic solution and quasi-regular arranged pores can be well organized in 20%HF/DMF solution. The luminescence shows fresh porous silicon can emit the red luminescence at room temperature and quench after nanoporous layer destroyed.

Effect of Au on the Performance of Porous Silicon/V2O5 Nanorods Heterojunctions to NO2 Gas

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Analytical Techniques ◽  
Heating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.

Decorated CNT based on porous silicon for hydrogen gas sensing at room temperature

RSC Advances ◽  
2016 ◽  
Vol 6 (50) ◽  
pp. 44410-44414 ◽  
Author(s):  
Hamid Ghorbani Shiraz ◽  
Fatemeh Razi Astaraei ◽  
Somayeh Fardindoost ◽  
Zahra Sadat Hosseini
Keyword(s):  
Porous Silicon ◽  
Room Temperature ◽  
Gas Sensing ◽  
Hydrogen Gas

A new triple-component sensor for detection of H2 was developed based on porous silicon and CNTs.

Light Controlled Photoluminescence Relaxation in Porous Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
R. Czaputa ◽  
R. Fritzl ◽  
A. Popitsch
Keyword(s):  
Porous Silicon ◽  
Chemical Structure ◽  
Room Temperature ◽  
Relaxation Effect ◽  
Ambient Atmosphere ◽  
Surface Chemical ◽  
Dangling Bond ◽  
Nanoporous Silicon ◽  
Pl Intensity ◽  
Modification Of The Surface

ABSTRACTWe report results of photoluminescence (PL), FTIR and ESR investigations on nanoporous silicon (PS) where a reversible PL intensity relaxation effect in the chemically oxidised material is observed. To be activated the effect needs, however, additional preparation steps including light irradiation and ageing in ambient atmosphere. After illumination with visible light, the PL intensity is remarkably diminished. However it recovers in the dark within the time scale of minutes to hours under ambient atmosphere at room temperature. This cycle can be repeated several times. We show that the variation of the PL intensity is anticorrelated to an ESR signal attributed to silicon dangling bonds. From the IR spectrum, however, no significant change of the pore surface chemical structure can be observed during a cycle. Therefore we conclude that the variation of the PL intensity is rather controlled by a metastable change in the number of dangling bond centers than by modification of the surface chemistry in the porous silicon system.

Porous silicon near room temperature nanosensor covered by TiO 2 or ZnO thin films

2008 ◽  
Author(s):  
Vladimir M. Aroutiounian ◽  
Valery M. Arakelyan ◽  
Vardan Galstyan ◽  
Khachatur Martirosyan ◽  
Patrick Soukiassian
Keyword(s):  
Thin Films ◽  
Porous Silicon ◽  
Room Temperature ◽  
Zno Thin Films

Fast Photoluminescence from Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
V. Petrova-Koch ◽  
T. Muschik ◽  
D. I. Kovalev ◽  
F. Koch ◽  
V. Lehmann
Keyword(s):  
Porous Silicon ◽  
Response Time ◽  
Spectral Range ◽  
Luminescence Band ◽  
Room Temperature ◽  
Internal Surface ◽  
Porous Si ◽  
Time Resolved ◽  
Processed Material ◽  
Defect Luminescence

ABSTRACTTime-resolved studies of the visible photoluminescence in porous silicon with three different coverages of the internal surface are reported. We use aged, naturally oxidized porous Si (oxihydride), rapid thermal processed material (oxide) and samples stored in HF (pure hydride). A new, fast luminescence band in the blue-green spectral range and with response time less than 100 ns is observed at room temperature in each of the samples, although with different intensities. The observations prove that this is not an oxide-defect luminescence. We speculate on mechanisms for the origin of the fast luminescence in nanometer-size crystallites of Si.

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