Defects and diffusion in high purity silicon for detector applications

Abstract

In this contribution we review some recent results on defects occurring after irradiation and thermal treatment of silicon detectors for ionizing radiation. In particular, the annealing of the prominent divacancy centre and the concurrent growth of a new double acceptor centre, assigned to the divacancyoxygen pair, is treated in detail. The detectors were fabricated using oxygenated high purity float zone (FZ) silicon wafers of n-type in order to improve the radiation hardness. The results obtained have important implication on our current understanding of the degradation of silicon detectors at high radiation fluences and suggest that a new concept for optimised impurity/defect engineering needs to be developed.

Morphological, optical and electrochromic properties of dry-lithiated nanostructured WO3 thin films

“…The presence of carbon C(1s) peak was observed at about 284.5 eV which was due to atmospheric contamination or the sample handling prior to XPS measurements (not shown in the figure). The spectra show characteristic doublet 4f 7/2 and 4f 5/2 which is caused by spin orbit splitting in WO 3 . The core level binding energies corresponding to 4f 7/2 and 4f 5/2 are found to be of 35.84 eV and 37.99 eV, respectively (shown in Fig.…”

“…Among transition metal oxides, for example, vanadium pentoxide (V 2 O 5 ), molybdenum trioxide (MoO 3 ) and tungsten trioxide (WO 3 ), the researchers have expanded their consideration towards WO 3 because of its high stability, wide bandgap, high coloration efficiency and relatively low cost. Moreover, WO 3 has distinct physical and chemical properties [1,2] that make it suitable for electrochromic devices, selective catalyst for oxidation and reduction reactions [3][4][5][6], environmental monitoring, gas sensing devices [7][8][9][10], transparent conducting electrodes, optical smart windows, display devices [11][12][13][14]. The combination of these solid state materials with thin film technology has significantly reduced the size of the devices and hence, improved the efficiency of the devices for various scientific and technological applications.…”

“…WO 3 thin films show coloration in both amorphous as well as crystalline states due to absorption and reflectance modulation, respectively [1] under certain electrochemical conditions. This property allows WO 3 for its practical applications, such as energy saving windows, solar roofing, antiglare * E-mail: kvmsvu@gmail.com rear-view mirrors or advertising panels [15,16]. Electrochromism is a property of a material whose color is changed reversibly by the direction of an applied electromotive force.…”