Influence of hydrogen on optical spectra of hydrogenated CdTe

Jacek Polit 1E Sheregii 1J Cebulski 1Malgorzata M. Pociask 1A Kisiel 2Andrzej Mycielski 3Jerzy Morgiel 4Augusto Marcelli 5M Piccinini 5M Cestelli Guidi B V. Robouch Victor Savchyn I. I. Izhnin 6A Nucara 7Paweł Zajdel 

1. University of Rzeszow, Institute of Physics, Rejtana 16, Rzeszów 35-310, Poland
2. Jagiellonian University, Institute of Physics (IF UJ), Reymonta 4, Kraków 30-059, Poland
3. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
4. Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences (IMIM PAN), Reymonta 25, Kraków 30-059, Poland
5. °Laboratori Nazionali Frascati INFN (INFN), Via E. Fermi 40, Frascati 00044, Italy
6. R&D Institute for Materials SRC "Carat", Lviv, Ukraine
7. Dipartimento di Fisica and Unita' INFM, Universita' di Roma "La Sapienza", Piazzale Aldo Moro 2, Roma 00185, Italy

Abstract

The presence of oxygen impurity in semiconducting materials affects the electrical properties of crystals and significantly limits their application. To remove oxygen impurity, ultra-pure hydrogen is used while growing Te-containing crystals such as CdTe, CdZnTe, and ZnTe. The hydrogenation of CdTe crystals is a technological process that purifies the basic material from oxygen, mainly cadmium and tellurium oxide compounds incorporated in CdTe crystalline lattice. In the present work we analyses the deformations induced by hydrogen and oxygen atoms in CdTe crystals looking at their influence on the near fundamental band (NFB), middle infrared (MIR) and far infrared (FIR) reflectivity spectra as well as on cathodoluminescence (CL) spectra. Comparison of the hydrogenated CdTe phonon structure profiles confirms the presence of hydrogen atoms bounded inside the lattice.The possible localization of hydrogen and oxygen ions within the tetrahedron coordinated lattice is discussed in the framework of a model that shows a good agreement with recent NFB, MIR and FIR experiments carried out on hydrogenated CdTe crystals. Measured reflection spectra in the wavelength range 190-1400 nm (NFB) indicate the appearance in CdTe(HM) and CdTe(HL) of additional maxima at 966 nm related to the electron transitions from level about 0.2 eV above the valence band. The CL spectra confirmed existence of this electron level. We present a possible H2 alignment similar to the single H model i.e., over the face (at about 0.38 Å). For this model the angle from the central atom to the H atoms is equal to 64° which is also close to the bonding angle of CdH2. The propose model was verified by TEM images.

Related papers
  1. Discontinuity of the phonon mode frequency temperature dependence caused by a zero-gap state in HgCdTe alloys
  2. Influence of hydrogen on hydrogenated cadmium telluride optical spectra
  3.  Far-infrared reflectivity as a probe of point defects in Zn- and Cd-doped HgTe
  4. SR a brilliant sources for solid-state researches in the IR and far-IR energy domain 
  5. Additional  Phonon Modes related to intrinsic defects in CdHgTe
  6. Solid-phase synthesis and preliminary biological investigation of arylpiperazine library as 5-HT1A and 5-HT2A receptor ligands
  7. Phonon and vibrational spectra of real crystals obtained using the synchrotron radiation
  8. HRTEM and TEM studies of amorphous structures in ZrNiTiCu base alloys obtained by rapid solidification or ball milling
  9. ZnO homoepitaxial growth by Atomic Layer Epitaxy technique.
  10. Structural and Electric Fieeld-Induced Properties of the narrow-Gap Semiconductor ZnCdHgTe Thin Films
  11. Preparation of the ZnO substrate surface
  12. TEM Characterization of Thin-Layered Materials
  13. Electrical contacts to semi-insulating (Cd,Mn)Te:V
  14. Microstructure and micro mechanical properties of multilayer Cr/CrN, PLD coatings
  15. Search for New Metallic Glass Compositions in NiZrTi Base Alloys Near Multicomponent Eutectic Positions
  16. Effect of the Annealing Atmosphere on the Quality of ZnO Crystal Surface
  17. Structure properties of bulk ZnO crystals
  18. Materials requirements in the group - CdTe, CdZnTe and CdMnTe - and recent advances for X-ray and gamma-ray applications.
  19. Applications of the II-VI semimagnetic semiconductors
  20. Is the (Cd,Mn)Te crystal a prospective material for X-ray and γ-ray detectors?
  21. The local crystalline structure of ZnCdTe alloys obtained by Far Infrared Synchrotron Radiation measurements
  22. Defects induced by oxygen and hydrogen in CdTe crystals
  23. ELECTRICAL AND OPTICAL PROPERTIES OF ZnO AND ZnO:Cr CRYSTALS, GROWN BY CVT METHOD
  24. Structural and optical characterization of epitaxial layers of CdTe/PbTe grown on BaF2 (111) substrates
  25. Low-frequency magnons and phonons in hexagonal MnTe
  26. HIGH PRESSURE ANNEALING-INDUCED REDUCTION IN DEGREE OF COMPENSATION IN (Zn,Mn)Te CRYSTALS
  27. CVT contactless growth of ZnO crystals
  28. Multi- layer composite based on amorphous materials and quasicrystals, deposited by laser ablation
  29. Properties of MBE CdxHg1-xTe/GaAs structures modified by ion-beam milling
  30. Mn doped ZnTe (110) (1x1) surface in Resonant Photoemission study
  31. Differential Reflectivity and Photoemission study of ZnTe and CdTe(110) surface

Presentation: Poster at E-MRS Fall Meeting 2006, Symposium F, by Jacek Polit
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-23 14:53
Revised:   2006-05-24 11:20
Google
 
Web science24.com
© 1998-2008 pielaszek research, all rights reserved Powered by the Conference Engine