کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1814850 1025656 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electrical and optical properties of thermally evaporated Ge20In5Se75 films
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Electrical and optical properties of thermally evaporated Ge20In5Se75 films
چکیده انگلیسی
Thin films of Ge20In5Se75 were prepared by the conventional thermal evaporation technique of presynthesize material on pyrographite and glass substrate. The chemical composition of the films has been checked using energy dispersive X-ray spectrometry. X-ray diffraction measurements have shown that Ge20In5Se75 in powder and thin film form has an amorphous nature. Electrical measurements included the electrical conductivity and I-V characteristics of amorphous films. The electrical conductivity was found to increase with increasing temperature, and to decrease with increasing film thickness. The obtained results showed that the electrical conduction activation energy has two values of ΔEI and ΔEII indicating the presence of two different conduction mechanisms. The I-V characteristics of films are typical for a memory switch. The mean value of the threshold voltage Vth decreases with increasing temperature and increases with increasing film thickness. The switching voltage activation energy (ε) was determined. Agreement between the obtained value of ratio (ε/ΔEII) with its value obtained theoretically on the basis of an electrothermal model was found. The spectral and optical parameters have been determined using spectrophotometric measurements of transmittance and reflectance in the wavelength range 400-2500 nm. The optical constants (refractive index (n), absorption index (k) and absorption coefficient (α)) have been determined. An allowed indirect transition with optical energy gap Egopt of 1.76 eV has been found.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 403, Issue 1, 1 January 2008, Pages 16-24
نویسندگان
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