Room-temperature photoluminescence spectrum from β-FeSi2 films

Author(s):  
Kensuke Akiyama ◽  
Yoshihisa Matsumoto ◽  
Hiroshi Funakubo
2010 ◽  
Vol 24 (10) ◽  
pp. 945-951 ◽  
Author(s):  
LIWEI WANG ◽  
ZHENG XU ◽  
SULING ZHAO ◽  
LIFANG LU ◽  
FUJUN ZHANG

ZnO : V thin films with different doping concentration (0%, 1.8%, 3.9%, 6.8%, 10%, and 13%) were fabricated by direct current magnetron sputtering. The X-ray diffraction patterns show that the wurzite structure changed with doping concentration. Furthermore, we could not find any vanadium cluster or phase separation in the X-ray diffraction patterns. The photoluminescence of ZnO : V with different vanadium concentration was investigated. The room temperature photoluminescence spectrum indicates that the films have purple band with 370 nm and the bands with 475 and 490 nm. The peak intensity of room temperature photoluminescence spectrum was affected by vanadium contents and its position remained stable. The intensity of band with 370 nm increases with raising the vanadium concentration and then decreases. The hysteresis behavior indicates that films were ferromagnetic at 50 K. Room temperature ferromagnetism was observed for the film with the doping concentration at 6.8%. However, in this case almost no hysteresis is noticeable. The results implied that the doping concentration and crystalline microstructure influence strongly the film's magnetic characteristics. Increasing the vanadium content in the film caused the degradation of the magnetic ordering.


2008 ◽  
Vol 22 (04) ◽  
pp. 417-422 ◽  
Author(s):  
ALWAN M. ALWAN ◽  
OMAR A. ABDULRAZAQ

The photoluminescence spectrum of the freshly photosynthesized porous silicon (PS) has been investigated. This measurement was repeated after three and six months for the same sample after storage under ambient condition (open air at room temperature). Photoluminescence (PL) measurements of the stored PS show different peak positions and intensity width as compared with the results of the fresh PS. A blue shift in PL peak positions with aging time was observed. PL relative intensity is strongly diminished after 6 months of aging. Dark I-V characteristics of Al/PS/n - Si/Al structure shows a behavior of PS/n - Si isotype heterojunction for fresh device and a MIS (metal-insulator-semiconductor) device due to contribution of Al/PS Schottky barrier after aging, essentially after 6 months.


1994 ◽  
Vol 358 ◽  
Author(s):  
T. Van Buuren ◽  
S. Eisebitt ◽  
S. Patitsas ◽  
S. Ritchie ◽  
T. Tiedje ◽  
...  

ABSTRACTThe peak energy of the room temperature photoluminescence of porous silicon is compared with the bandgap determined from photoelectron spectroscopy measurements for a series of porous silicon samples prepared under different conditions. The photoluminescence bandgap is found to be smaller than the photoelectron spectroscopy bandgap, but exhibits the same trend with preparation conditions. The width of both the photoluminescence spectrum and the L-absorption edge increases when the current density during the preparation is increased or the sample is allowed to soak in HF after preparation.


2015 ◽  
Vol 30 ◽  
pp. 96-105
Author(s):  
V. Andal ◽  
G. Buvaneswari

Surfactant assisted synthetic route was followed to prepare silver selenide (β-Ag2Se) nanoparticles. The effect of three different surfactants viz., Triton X100, SDS and CTAB in the formation of silver selenide nanoparticles had been examined. Pure and crystalline β-Ag2Se nanophase was obtained in the presence of Triton X100 and SDS. However, the presence of CTAB leads to metallic silver formation. Nano Composite of β-Ag2Se and ZnS was fabricated in the presence of glycine as a molecular linker. The products were characterized by different techniques such as XRD, FT-IR, SEM and TEM. Room temperature photoluminescence spectrum of the ZnS/ β-Ag2Se nanocomposite exhibited two emission peaks at around 286 nm and 392 nm with enhanced intensity (lex= 250 nm).


2003 ◽  
Vol 769 ◽  
Author(s):  
Asha Sharma ◽  
Deepak ◽  
Monica Katiyar ◽  
Satyendra Kumar ◽  
V. Chandrasekhar ◽  
...  

AbstractThe optical degradation of polysilane copolymer has been studied in spin cast thin films and solutions using light source of 325 nm wavelength. The room temperature photoluminescence (PL) spectrum of these films show a sharp emission at 368 nm when excited with a source of 325 nm. However, the PL intensity deteriorates with time upon light exposure. Further the causes of this degradation have been examined by characterizing the material for its transmission behaviour and changes occurring in molecular weight as analysed by GPC data.


ACS Photonics ◽  
2021 ◽  
Author(s):  
Tomojit Chowdhury ◽  
Kiyoung Jo ◽  
Surendra B. Anantharaman ◽  
Todd H. Brintlinger ◽  
Deep Jariwala ◽  
...  

2010 ◽  
Vol 663-665 ◽  
pp. 324-327
Author(s):  
Chao Song ◽  
Rui Huang

The germanium film and Ge/Si multilayer structure were fabricated by magnetron sputtering technique on silicon substrate at temperatures of 500°C. Raman scattering spectroscopy measurements reveal that the nanocrystalline Ge occurs in both kinds of samples. Furthermore, from the atomic force microscopy (AFM) results, it is found that the grain size as well as spatially ordering distribution of the nc-Ge can be modulated by the Ge/Si multilayer structure. The room temperature photoluminescence was also observed in the samples. However, compared with that from the nc-Ge film, the intensity of PL from the nc-Ge/a-Si multilayer film becomes weaker, which is attributed to its lower volume fraction of crystallized component.


2021 ◽  
pp. 1903080
Author(s):  
Surendra B. Anantharaman ◽  
Joachim Kohlbrecher ◽  
Gabriele Rainò ◽  
Sergii Yakunin ◽  
Thilo Stöferle ◽  
...  

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