Fabrication of double mesa structures from superconducting Bi2Sr2CaCu2O8+d by e-beam lithography for terahertz emission
tarafından
 
Demirhan, Yasemin.

Başlık
Fabrication of double mesa structures from superconducting Bi2Sr2CaCu2O8+d by e-beam lithography for terahertz emission

Yazar
Demirhan, Yasemin.

Yazar Ek Girişi
Demirhan, Yasemin.

Yayın Bilgileri
[s.l.]: [s.n.], 2011.

Fiziksel Tanımlama
xii, 87 leaves.: ill. + 1 computer laser optical disc.

Özet
Terahertz radiation is part of the electromagnetic spectrum lying between microwaves and the far-IR. This region has frequencies ranging from 0.1 - 10 THz and wavelengths from 3 mm to 0.03 mm. We work on a frequency tunable solid state device to meet the needs of continuous, coherent, powerful terahertz emission sources that fill practically important terahertz gap. Among the cuprates, single crystal of Bi2Sr2CaCu2O8+ (Bi2212) is a potential candidate of compact solid state devices designed for generating electromagnetic waves in terahertz frequency range. Bi2212 crystals are consisting of natural arrays in the form of identical layers called intrinsic Josephson junctions (IJJ). In this study, under optimized doping conditions we aimed to investigate powerful terahertz emission. THz emission in the μW range can be obtained fabricating rectangular-shaped mesa structures on the Bi2212 crystal. In the experimental procedure, in order to obtain various doping levels, we annealed the high temperature superconducting Bi2212 single crystals at various temperatures in vacuum or under argon flow. By using the thermal evaporation, optic and electron beam lithography, ion beam etching techniques single and double mesa structures were fabricated. For the e-beam lithography process, we optimized and improved the required parameters. After the mesa fabrication, the exact dimensions of the mesas were obtained using surface profilometer and atomic force microscope. In order to characterize the Bi2212 mesas,by three probe contact c-axis resistance versus temperature (R-T), and current-voltage behavior (I -V) were measured in a He flow cryostat. Some of the hysteretic quasiparticle branches are seen in the I-V characteristics of Bi2212 crystals.

Konu Başlığı
Terahertz spectroscopy.
 
Superconductors [
 
Lithography, Electron beam.

Yazar Ek Girişi
Özyüzer, Lütfi.

Tüzel Kişi Ek Girişi
İzmir Institute of Technology. Physics.

Tek Biçim Eser Adı
Thesis (Master)--İzmir Institute of Technology:Physics.
 
İzmir Institute of Technology:Physics--Thesis (Master).

Elektronik Erişim
Access to Electronic Version.


LibraryMateryal TürüDemirbaş NumarasıYer NumarasıDurumu/İade Tarihi
IYTE LibraryTezT000966QC454.T47 D378 2011Tez Koleksiyonu