A multi-spectroscopic study of luminescence sensitivity changes in natural quartz induced by high-temperature annealing

Bulur, Enver
Botter-Jensen, L
Smith, G
The luminescence sensitivity of natural quartz is significantly enhanced if heated beyond the first and second crystal phase transitions, in the temperature range 500-1100 degreesC. This work employs a number of complementary spectroscopic methods to obtain a fuller understanding of the mechanisms of this sensitization process. Spectrally resolved radioluminescence is used to study the role played by hole trapping recombination sites. Linearly-modulated optically stimulated luminescence is used to probe a number of different optically active electron donor defects. Spectrally resolved thermoluminescence simultaneously monitors the processes of electron eviction from donor centres, and recombination at acceptor sites. Finally, high-frequency electron paramagnetic resonance is used to monitor changes in population and structure of defects present within the lattice, some of which partake (either directly or indirectly) in the emission processes of the samples. The work leads to the conclusion that luminescence is generally sensitized in quartz by the removal of oxygen vacancy E' centres (which act either as non-radiative recombination centres, or as luminescence centres emitting in the deep UV, beyond the range of our instrumentation). In some samples, further luminescence enhancement is accompanied by heat induced creation of donor defects. The spectral results show that, not only is there competition between the accepters for recombining electrons, but also that the emission undergoes significant thermal quenching at elevated temperatures. Comparison of the radioluminescence and thermoluminescence measurements enables the quenching energies of two emission bands (360, 470 nm) to be obtained directly.


Assessment of InSb photodetectors on Si substrates
Ozer, S; Beşikci, Cengiz (IOP Publishing, 2003-03-07)
We present the detailed characteristics of small area (33 x 33 mum(2)) InSb photodiodes grown on GaAs coated Si substrates by molecular beam epitaxy. In spite of very large lattice mismatch, 80 K peak detectivity of similar to1 x 10(10) cm Hz(1/2) W-1 has been measured under backside illumination without anti-reflection coating. Differential resistance at 80 K is limited by Ohmic leakage under small reverse bias and trap assisted tunnelling (TAT) under moderately large reverse bias. In the temperature range...
Electrical and photoelectrical properties of Ag-In-Se thin films evaporated by e-beam technique
ÇOLAKOĞLU, Tahir; Parlak, Mehmet (IOP Publishing, 2009-02-07)
In this study, the electrical and photoelectrical properties of the Ag-In-Se thin films deposited by the e-beam technique have been investigated by carrying out temperature dependent conductivity, photoconductivity under different illumination intensities and photoresponse measurements between 380 and 1050 nm, as a function of annealing temperature. The measured conductivity values of the films at room temperature depending on the annealing temperatures vary in the range 1.9 x 10(-6)-5.2 Omega(-1) cm(-1). A...
Perturbation analysis of sheath evolution, with application to plasma source ion implantation
Bektursunova, RM; Demokan, O (IOP Publishing, 2001-02-07)
A perturbation model has been developed to describe the evolution of an expanding plasma sheath around a cathode after a high-voltage negative pulse is applied to the cathode, simulating the conditions in devices such as those used for plasma source ion implantation. The set of governing equations consists of two coupled collisionless fluid equations for ions, and Poisson's equation and Boltzmann's assumption for electrons. The time-dependent, self-consistent expressions for the potential, ion density and i...
Analysis of the Spontaneous Polarization and the Dielectric Constant Near the Ferroelectric Phase Transition in TSCC
Yurtseven, Hasan Hamit (Informa UK Limited, 2008-01-01)
The temperature dependence of the spontaneous polarization and the dielectric constant has been analyzed for the fixed pressures of 0.001,1 and 2.2 kbar close to the phase transitions in TSCC. This analysis is performed using the experimental data for TSCC according to a power-law formula. From our analysis, using the experimental data for the spontaneous polarization, we deduce the values of the critical exponent = 0.32 (1 bar), 0.28 (1 kbar) and 0.26 (2.2 kbar) for the spontaneous polarization near the tr...
A sol-gel derived AgCl photochromic coating on glass for SERS chemical sensor application
Volkan, Mürvet; Vo-Dinh, T (Elsevier BV, 2005-05-13)
A new optically translucent material has been prepared that acts as a substrate for surface-enhanced Raman spectroscopy. This material is a silica matrix, synthesized by the sol-gel method and containing in situ precipitated AgCl particles which serve as precursors for nanoparticles of elemental silver. Reduction of AgCl to silver nanoparticles is achieved by UV irradiation. The SERS-active medium was distributed on glass supports (cover glass slips, 0.5 turn thick), hence producing thin, sturdy, and optica...
Citation Formats
T. SCHILLES et al., “A multi-spectroscopic study of luminescence sensitivity changes in natural quartz induced by high-temperature annealing,” JOURNAL OF PHYSICS D-APPLIED PHYSICS, pp. 722–731, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/42954.