Unified potential fluctuations model for photoluminescence spectra at room temperature—Cu(In,Ga)Se2 thin films

Copper selenide thin films of three different thicknesses have been prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by UV-VIS-NIR spectroscopy and photoluminescence spectroscopy. Surface morphology was investigated by field-emission scanning electron microscopy. Copper selenide exhibits both direct and indirect transitions. The band gap for direct transition is found to be ~2.7 eV and that for indirect transition it is ~1.70 eV. Photoluminescence spectra of copper selenide thin films have also been analyzed, which show emission peaks at 530, 550, and 760 nm. The latter corresponds to indirect transition in investigated material.

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Size Dependent Electroluminescence from CdSe Nanocrystallites (Quantum Dots)

MRS Proceedings ◽

10.1557/proc-358-707 ◽

1994 ◽

Vol 358 ◽

Cited By ~ 2

Author(s):

B.O. Dabbousi ◽

O. Onitsuka ◽

M.F. Rubner ◽

M.G. Bawendi

Keyword(s):

Thin Films ◽

Quantum Dots ◽

Room Temperature ◽

Variable Temperature ◽

Cryogenic Temperatures ◽

Photoluminescence Spectra ◽

Size Dependent

ABSTRACTWe obtain spectrally narrow (FWHM < 40 nm) electroluminescence from nearly monodisperse CdSe nanocrystallites (quantum dots) incorporated into thin films of polyvinyl carbazole (PVK) and an oxadiazole derivative (PBD) sandwiched between aluminum and ITO electrodes. The electroluminescence and photoluminescence spectra are nearly identical at room temperature and are tunable from ∼530 nm to ∼650 nm by varying the size of the dots. Voltage studies at 77K indicate that while only the dots electroluminesce at the lower voltages, both the dots and the PVK matrix electroluminesce at higher applied voltages. Variable temperature studies indicate that the electroluminescence efficiency increases substantially as the films are cooled down to cryogenic temperatures.

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In2O3 Thin Films Prepared on TiAlN Substrates Using a Triethylindium and Oxygen Mixture

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.1597 ◽

2007 ◽

Vol 124-126 ◽

pp. 1597-1600

Author(s):

Hyoun Woo Kim ◽

Sun Keun Hwang ◽

Won Seung Cho ◽

Tae Gyung Ko ◽

Seung Yong Choi ◽

...

Keyword(s):

Thin Films ◽

Substrate Temperature ◽

Room Temperature ◽

Light Emission ◽

Xrd Analysis ◽

Oxygen Mixture ◽

Photoluminescence Spectra ◽

Sem Images ◽

Room Temperature Photoluminescence ◽

Visible Light Emission

This paper reports the fabrication of indium oxide (In2O3) films using a triethylindium and oxygen mixture. The deposition has been carried out on TiAlN substrates (200-350°C). We have established the correlation between the substrate temperature and the structural properties. The films deposited at 300-350°C were polycrystalline, whereas those deposited at 200°C was close to amorphous. XRD analysis and SEM images indicated that the films grown at 350°C had grained structures with the (222) preferred orientation. The room-temperature photoluminescence spectra of the In2O3 films exhibited a visible light emission.

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Characterization of Nd:Y3Al5O12 Thin Films Prepared by Electron Beam Evaporation Deposition

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.320.150 ◽

2013 ◽

Vol 320 ◽

pp. 150-154

Author(s):

Hao Ren ◽

Qun Zeng ◽

Xi Hui Liang

Keyword(s):

Thin Films ◽

Electron Beam ◽

Room Temperature ◽

Electron Beam Evaporation ◽

Photoluminescence Spectra ◽

X Ray Diffraction ◽

X Ray ◽

Surface Morphologies ◽

Ingaas Detector

Nd:YAG thin films have been prepared on Si (100) substrates by electron beam evaporation deposition. The surface morphologies, crystalline phases and optical properties of the Nd:YAG thin films were characterized by x-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, and spectrophotometer. The crystallization of Nd:YAG thin films was improved after annealing at 1100 °C for 1 hour in vacuum. Excited by a Ti:sapphire laser at 808 nm, photoluminescence spectra of Nd:YAG thin films were measured at room temperature, and the transition of4F3/24I11/2of Nd3+in YAG in the region of 1064 nm were detected by a liquid nitrogen cooled InGaAs detector array.

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Luminescence from Germanium and Germanium on Silicon

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.205-206.383 ◽

2013 ◽

Vol 205-206 ◽

pp. 383-393 ◽

Cited By ~ 2

Author(s):

Tzanimir Arguirov ◽

Martin Kittler ◽

Michael Oehme ◽

Nikolay V. Abrosimov ◽

Oleg F. Vyvenko ◽

...

Keyword(s):

Thin Films ◽

Room Temperature ◽

Threshold Current ◽

Threshold Current Density ◽

Excitation Level ◽

The Other ◽

Photoluminescence Spectra ◽

Si Substrates ◽

Similar Dependence ◽

Direct Band

We present an overview on generation of direct gap photo- and electroluminescence in Ge bulk wafers, Ge thin films deposited on Si, and Ge p-i-n diodes prepared on Si substrates. We analyzed the emission in a spectral range from 0.45 eV to 0.95 eV, covering the radiation caused by direct gap transitions, the indirect one, and also the luminescence related to transition on dislocations. The temperature and excitation level strongly influence the intensities of direct and indirect photoluminescence in bulk samples. As it could be expected, high temperature and excitation favour the generation of direct gap luminescence. Intrinsic bulk Ge shows a quadratic dependence of the direct gap luminescence on the excitation and a sub-quadratic one for the indirect. The photoluminescence spectra taken from intrinsic Ge on Si layers show features related to dislocations. There are two spectral regions associated with dislocation recombination. At room temperature one is at around 0.45 eV and the other at 0.72 eV. We found strong direct gap radiation from the Ge p-i-n diodes with intrinsic, highly dislocated active area (dislocation density of about 108-1010 cm-2). There is a threshold current density of 8 kA/cm2, at which the direct band luminescence becomes a super-quadratic. The dependence of the radiation intensity on the excitation is governed by a power law with exponent of 1.7 before reaching that threshold and 4.5 after exceeding it. Above the threshold the dislocation radiation shows similar dependence on the excitation as the direct band luminescence.

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A Study of Structural and Photoluminescence for Al-Doped CdO Thin Films

Journal of Spectroscopy ◽

10.1155/2016/5127348 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Bong Ju Lee ◽

Jin Jeong

Keyword(s):

Thin Films ◽

Room Temperature ◽

Deposition Time ◽

Processing Parameters ◽

Photoluminescence Spectra ◽

X Ray Diffraction ◽

Light Emitting ◽

X Ray ◽

Grain Sizes ◽

Cdo Thin Films

Al-doped CdO thin films were prepared by radio frequency magnetron sputtering at different deposition time and substrate temperature. X-ray diffraction showed that the changes in the intensities of the (200), (220), and (311) planes followed a similar trend with increase in deposition time. The surface of the thin film was examined by scanning electron microscopy. Grain sizes of Al-doped CdO thin films increased significantly with increasing deposition time. The film thicknesses were 0.09, 0.12, 0.20, and 0.225 μm for the deposition times of 1, 2, 3, and 4 h, respectively. The photoluminescence spectra of the Al-doped CdO thin films were measured at room temperature. The photoluminescence wavelength changed in the sequence, green, blue, green, and blue, with increasing deposition time, which indicates that blue light emitting films can be fabricated by adjusting the processing parameters.

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Room Temperature Ultraviolet Photoluminescence from 800°C Thermally Oxidized Si1−x−yGexCy Thin Films on Si(100) Substrate

MRS Proceedings ◽

10.1557/proc-592-165 ◽

1999 ◽

Vol 592 ◽

Author(s):

X. M. Cheng ◽

Y. D. Zheng ◽

L. Zang ◽

X. B. Liu ◽

S. M. Zhu ◽

...

Keyword(s):

Thin Films ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Room Temperature ◽

Chemical Vapor ◽

Silicon Substrates ◽

Photoluminescence Spectra

ABSTRACTThe thermally oxidized Si1−x−yGexCy thin films were grown on silicon substrates by Plasma-enhanced Chemical Vapor Deposition (PECVD) and then wet oxidized at 800°C for 20 minutes. Photoluminescence spectra of the samples were measured at room temperature under 250nm excitation. Two ultraviolet photoluminescence bands with the peaks at ∼370nm and ∼396nm were observed in the oxidized samples. Possible mechanism of this photoluminescence is discussed.

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Low-temperature photoluminescence of CuSe2 nano-objects in selenium thin films

Processing and Application of Ceramics ◽

10.2298/pac1702127g ◽

2017 ◽

Vol 11 (2) ◽

pp. 127-135 ◽

Cited By ~ 4

Author(s):

Martina Gilic ◽

Milica Petrovic ◽

Jovana Cirkovic ◽

Novica Paunovic ◽

Svetlana Savic-Sevic ◽

...

Keyword(s):

Thin Films ◽

Band Gap ◽

Room Temperature ◽

Band Gaps ◽

Photoluminescence Spectra ◽

Indirect Transition ◽

Direct Transition ◽

Direct Band Gap ◽

Vis Spectroscopy ◽

Direct Band

Thin films of CuSe2 nanoparticles embedded in selenium matrix were prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by photoluminescence spectroscopy (T=20-300K) and UV-VIS spectroscopy (T = 300K). Surface morphology was investigated by scanning electron microscopy. The band gap for direct transition in CuSe2 was found to be in the range of 2.72-2.75 eV and that for indirect transition is in the range of 1.71-1.75 eV determined by UV-VIS spectroscopy. On the other hand, selenium exhibits direct band gap in the range of 2.33-2.36 eV. All estimated band gaps slightly decrease with the increase of the film thickness. Photoluminescence spectra of the thin films clearly show emission bands at about 1.63 and 2.32 eV at room temperature, with no shift observed with decreasing temperature. A model was proposed for explaining such anomaly.

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Photoluminescence characteristics of strontium titanate thin films prepared by spray pyrolysis

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v10n2.261 ◽

2014 ◽

Vol 10 (2) ◽

Author(s):

S. Aisah Mat ◽

Karim Deraman ◽

R. Hussin ◽

W. Nurulhuda W. Shamsuri ◽

Bakar Ismail ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Aqueous Solution ◽

Spray Pyrolysis ◽

Strontium Titanate ◽

Room Temperature ◽

Band Gap Energy ◽

Molar Ratio ◽

Photoluminescence Spectra ◽

Gap Energy

Strontium titanate, SrTiO3 thin films were successfully prepared by spray pyrolysis. The strontium titanate, STO precursor solid thin film were fabricated from an aqueous solution of Sr(NO3)2/[(CH3)2CHO]4Ti/HNO3 = 19:1:20 (molar ratio) at room temperature on a substrate. The as-deposited STO thin film with those annealed at different temperature were prepared. Photoluminescence spectra of thin films were obtained using Photoluminescence Spectrophotometer and optical properties were carried out by using Shimadzu Uv-Vis Spectrophotometer. In conclusion, the band gap energy and the bandwidth of thin films have been analysed. ________________________________________GRAPHICAL ABSTRACT

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Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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