103 research outputs found
Effect of Mn and Mg dopants on vacancy defect formation in ammonothermal GaN
We have applied positron annihilation spectroscopy to study the formation of Ga vacancy related defects in Mg and Mn doped bulk GaN crystals grown by the ammonothermal method. We show that Mn doping has little or no effect on the formation of Ga vacancies, while Mg doping strongly suppresses their formation, in spite of both dopants leading to highly resistive material. We suggest the differences are primarily due to the hydrogen-dopant interactions. Further investigations are called for to draw a detailed picture of the atomic scale phe-nomena in the synthesis of ammonothermal GaN.Peer reviewe
Study of variations of the carrier recombination and charge transport parameters during proton irradiation of silicon pin diode structures
Peer reviewe
SPECTROSCOPY OF DEFECTS IN NEUTRON IRRADIATED AMMONO-THERMAL GaN BY COMBINING PHOTOIONIZATION, PHOTOLUMINESCENCE AND POSITRON ANNIHILATION TECHNIQUES
In this work, pulsed photoionization as well as photoluminescence and positron annihilation spectroscopy were combined to detect different species of defects. The GaN crystals, grown by the ammono-thermal method, doped with Mn as well as Mg impurities and irradiated with different fluences of reactor neutrons, were examined to clarify the role of the technological and radiation defects. The evolution of the prevailing photoactive centres was examined by pulsed photoionization spectroscopy. Positron annihilation spectroscopy was applied to reveal vacancy-type defects.Peer reviewe
Analysis of trap spectra in LEC and epitaxial GaAs
Different methods of trap parameter measurement are analysed. Transient
photoconductivity and thermally stimulated effects were used to investigate the
influence of traps in LEC SI-GaAs and high resistivity epitaxial GaAs. The
peculiarities of the TSC were analysed and shown to be related to the influence
of crystal micro-inhomogeneities.Comment: Invited talk, 6-th Workshop on Gallium Arsenide and Related Compounds
June 22-26, 1998 Praha-Pruhonice, Czech Republi
RD39 Status Report 2009
RD39 Status Report 2009. CERN RD39 Collaboration is developing super-radiation hard cryogenic silicon detectors for applications of LHC experiments and their future upgrades. The activities of RD39 Collaboration were focused in 2009 on concept of charge injected detector (CID)
ΠΠΠΠΠΠ¦ΠΠΠΠΠ«Π ΠΠ’ΠΠΠ ΠΠΠΠΠΠΠΠ‘Π Π‘ΠΠΠ‘Π’ΠΠΠΠΠΠ ΠΠΠΠΠΠΠΠ£ΠΠΠΠ β ΠΠΠ‘ΠΠΠ ΠΠ Π ΠΠ ΠΠΠΠΠ p-Π’ΠΠΠ
With the use of deep level transient spectroscopy (DLTS) the effect of injection of minority charge carriers (electrons) on an annealing rate of self di-interstitial β oxygen (I2O) complex in silicon has been studied. The complex has been formed by irradiation of epitaxial boron-doped n+βp diode structures with alpha-particles at room temperature. It has been shown that the disappearance of this complex at room temperature begins at a direct current density of ~1.5 A/cm2. This characteristic current density has been found for 10 WΒ·cm p-type silicon when the total radiation defect density was less than 15 % of the initial boron concentration, a divalent hole trap with energy levels of Ev + 0.43 eV and Ev + 0.54 eV has been found to appear as a result of recombination-enhanced annealing of the I2O. When the I2O complex is annealed thermally, the concurrent appearance of an electron trap with an energy level of Ec β 0.35 eV has been observed. It has been shown that the divalent hole trap represents a metastable configuration (BH-configuration) of the bistable defect, whereas the electron trap is stab le in the p-Si configuration (ME-configuration). From the comparison of DLTS signals related to different defect configurations it is found that the ME-configuration of this bistable defect can be characterized as a center with negative correlation energy. It has been shown that the injection-stimulated processes make it very difficult to obtain reliable data on the formation kinetics of the bistable defect in the BH-configuration when studying the thermal annealing of the I2O complex.ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ Π½Π΅ΡΡΠ°ΡΠΈΠΎΠ½Π°ΡΠ½ΠΎΠΉ ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΊΠΎΠΏΠΈΠΈ Π³Π»ΡΠ±ΠΎΠΊΠΈΡ
ΡΡΠΎΠ²Π½Π΅ΠΉ (DLTS) Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ n+βp-ΡΡΡΡΠΊΡΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΈ Π½Π΅ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
Π½ΠΎΡΠΈΡΠ΅Π»Π΅ΠΉ Π·Π°ΡΡΠ΄Π° (ΡΠ»Π΅ΠΊΡΡΠΎΠ½ΠΎΠ²) Π½Π° ΠΎΡΠΆΠΈΠ³ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΡΠΎΠ±ΡΡΠ²Π΅Π½Π½ΠΎΠ΅ Π΄ΠΈΠΌΠ΅ΠΆΠ΄ΠΎΡΠ·Π»ΠΈΠ΅ β ΠΊΠΈΡΠ»ΠΎΡΠΎΠ΄ (I2O) Π² ΠΊΡΠ΅ΠΌΠ½ΠΈΠΈ, ΠΎΠ±Π»ΡΡΠ΅Π½Π½ΠΎΠΌ Π°Π»ΡΡΠ°-ΡΠ°ΡΡΠΈΡΠ°ΠΌΠΈ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π² Π»Π΅Π³ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΌ Π±ΠΎΡΠΎΠΌ ΠΊΡΠ΅ΠΌΠ½ΠΈΠΈ, ΠΈΠΌΠ΅ΡΡΠ΅ΠΌ ΡΠ΄Π΅Π»ΡΠ½ΠΎΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΠ΅ 10 ΠΠΌΒ·ΡΠΌ, ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΎΠ½Π½ΠΎ-ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΠΉ ΠΎΡΠΆΠΈΠ³ ΡΡΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΠΏΡΠΈ ΠΊΠΎΠΌΠ½Π°ΡΠ½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ Π½Π°ΡΠΈΠ½Π°Π΅ΡΡΡ ΠΏΡΠΈ ΠΏΠ»ΠΎΡΠ½ΠΎΡΡΠΈ ΠΏΡΡΠΌΠΎΠ³ΠΎ ΡΠΎΠΊΠ° ~1,5 Π/ΡΠΌ2. ΠΡΠΈ ΡΡΠΎΠΌ ΡΡΠΌΠΌΠ°ΡΠ½Π°Ρ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡ ΡΠ°Π΄ΠΈΠ°ΡΠΈΠΎΠ½Π½ΡΡ
Π΄Π΅ΡΠ΅ΠΊΡΠΎΠ² Π½Π΅ ΠΏΡΠ΅Π²ΡΡΠ°Π»Π° 15 % ΠΎΡ Π½Π°ΡΠ°Π»ΡΠ½ΠΎΠΉ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΠΈ Π±ΠΎΡΠ°. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΎΠ½Π½ΠΎ-ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π° I2O ΠΎΠ±ΡΠ°Π·ΡΠ΅ΡΡΡ Π΄Π²ΡΡ
Π²Π°Π»Π΅Π½ΡΠ½Π°Ρ Π΄ΡΡΠΎΡΠ½Π°Ρ Π»ΠΎΠ²ΡΡΠΊΠ° Ρ ΡΡΠΎΠ²Π½ΡΠΌΠΈ Ev + 0,43 ΡΠ ΠΈ Ev + 0,54 ΡΠ. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ Π² ΠΊΡΠ΅ΠΌΠ½ΠΈΠΈ Ρ-ΡΠΈΠΏΠ° ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ ΡΡΠ° Π»ΠΎΠ²ΡΡΠΊΠ° ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΠ΅Ρ ΡΠΌΠΈΡΡΠΈΠΈ Π΄ΡΡΠΎΠΊ ΠΌΠ΅ΡΠ°ΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΠΉ ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΠ΅ΠΉ Π±ΠΈΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΠ³ΠΎ Π΄Π΅ΡΠ΅ΠΊΡΠ° (BH-ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΡ). Π ΠΎΡΠ½ΠΎΠ²Π½ΠΎΠΉ ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΠΈ (ME-ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΡ) ΡΡΠΎΡ Π±ΠΈΡΡΠ°Π±ΠΈΠ»ΡΠ½ΡΠΉ Π΄Π΅ΡΠ΅ΠΊΡ ΠΏΡΠΎΡΠ²Π»ΡΠ΅Ρ ΡΠ΅Π±Ρ ΠΊΠ°ΠΊ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½Π°Ρ Π»ΠΎΠ²ΡΡΠΊΠ° Ρ ΡΡΠΎΠ²Π½Π΅ΠΌ Ec β 0,35 ΡΠ. ΠΠ° ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠΈ Π΄Π°Π½Π½ΡΡ
ΠΎΠ± ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΈ Π°ΠΌΠΏΠ»ΠΈΡΡΠ΄ ΡΠΈΠ³Π½Π°Π»Π° DLTS Π±ΠΈΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΠ³ΠΎ Π΄Π΅ΡΠ΅ΠΊΡΠ° Π² ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΡΡ
ΡΠ΄Π΅Π»Π°Π½ Π²ΡΠ²ΠΎΠ΄, ΡΡΠΎ Π² ME-ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΠΈ ΠΎΠ½ Π²Π΅Π΄Π΅Ρ ΡΠ΅Π±Ρ ΠΊΠ°ΠΊ ΡΠ΅Π½ΡΡ Ρ ΠΎΡΡΠΈΡΠ°ΡΠ΅Π»ΡΠ½ΠΎΠΉ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΠ½Π΅ΡΠ³ΠΈΠ΅ΠΉ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π½Π°Π»ΠΈΡΠΈΠ΅ ΠΈΠ½ΠΆΠ΅ΠΊΡΠΈΠΎΠ½Π½ΠΎ-ΡΡΠΈΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΏΡΠΎΡΠ΅Ρ- ΡΠΎΠ² ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ Π·Π°ΡΡΡΠ΄Π½ΡΠ΅Ρ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ Π΄ΠΎΡΡΠΎΠ²Π΅ΡΠ½ΡΡ
Π΄Π°Π½Π½ΡΡ
ΠΎ ΠΊΠΈΠ½Π΅ΡΠΈΠΊΠ΅ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ Π±ΠΈΡΡΠ°Π±ΠΈΠ»ΡΠ½ΠΎΠ³ΠΎ Π΄Π΅ΡΠ΅ΠΊΡΠ° Π² BH-ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΠΈ ΠΏΡΠΈ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΈ ΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΎΡΠΆΠΈΠ³Π° ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΡΠΎΠ±ΡΡΠ²Π΅Π½Π½ΠΎΠ΅ Π΄ΠΈΠΌΠ΅ΠΆΠ΄ΠΎΡΠ·Π»ΠΈΠ΅ β ΠΊΠΈΡΠ»ΠΎΡΠΎΠ΄
In situ variations of the scintillation characteristics in GaN and CdS layers under irradiation by 1.6 MeV protons
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