30 مهر 1398
داريوش سوري

داریوش سوری

مرتبه علمی: دانشیار
نشانی:
تحصیلات: دکترای تخصصی / فیزیک ماده چگال
تلفن:
دانشکده: علوم پایه

مشخصات پژوهش

عنوان
A New Method for the Determination of Optical Band Gap and the Nature of Optical Transitions in Semiconductors
نوع پژوهش مقاله چاپ شده
کلیدواژه‌ها
DASF method
سال
2015
مجله APPLIED PHYSICS B-LASERS AND OPTICS
پژوهشگران داریوش سوری

چکیده

A new method (named as DASF: Derivation of absorption spectrum fitting) is proposed for the determination of optical band gap and the nature of optical transitions in semiconductors; this method only requires the measurement of the absorbance spectrum of the sample, avoiding any needs to film thickness or any other parameters. In this approach, starting from absorption spectrum fitting (ASF) procedure and by the first derivation of the absorbance spectrum, the optical band gap and then the type of optical transition can be determined without any presumption about the nature of transition. DASF method was employed on (60−x)V2O5–40TeO2–xAg2O glassy systems (hereafter named as TVAgx), in order to confirm the validity of this new method. For the present glasses, the DASF results were compared with the results of ASF procedure for, confirming a very good agreement between these approaches. These glasses were prepared by using the melt quenching and blowing methods to obtain bulk and film samples, respectively. Results show that the optical band gap variation for TVAgx glasses can be divided into two regions, 0 ≤ x ≤ 20 and 20 ≤ x ≤ 40 mol%. The optical band gap has a maximum value equal to 2.72 eV for x = 40 and the minimum value equal to 2.19 eV for x = 40. Also, some physical quantities such as the width of the band tails (Urbach energy), glass density, molar volume, and optical basicity were reported for the under studied glasses.