Effect of Trap Levels and Defect Inhomogeneities on Carrier Transport in SiC Crystals and Radiation Detectors

نویسندگان

  • V. Kažukauskas
  • V. Kalendra
چکیده

We present investigation of carrier transport and trapping in 4H-SiC single crystals and high-energy radiation detectors. SiC detectors were produced from bulk vanadium-compensated semi-insulating single crystal 4H-SiC and provided with nickel ohmic and titanium Schottky contacts. The prevailing defect levels were revealed by means of thermally stimulated current and thermally stimulated depolarization methods and their advanced modification — multiple heating technique. From I−V measurements a Schottky barrier height of ≈ 1.9 eV was found. In 4H-SiC:Va the following thermal activation values were deduced: 0.18–0.19 eV, 0.20–0.22 eV, 0.3–0.32 eV, 0.33–0.41 eV, and 0.63 eV. The maximum with activation energy of 0.33–0.41 eV appears below 125 K and most probably is caused by thermal carrier generation from defect levels. In contrast, the first three maxima with lowest activation energies, which appear at higher temperatures, are likely associated with material inhomogeneities causing potential fluctuations of the band gap. The existence of different polarization sources in different temperature ranges is also demonstrated by thermally stimulated depolarization.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Investigation of Carrier Transport in GaN Single Crystals and Radiation Detectors by Thermally Stimulated Methods

We investigated single crystals of GaN and thin film GaN radiation detectors by thermally stimulated currents and thermally stimulated depolarization methods in order to characterize carrier transport properties as influenced by material defect structure. In thick GaN no expressed structure of the thermally stimulated current spectra was observed in the temperature range from 100 K up to 350 K,...

متن کامل

Effects of Dislocation Walls on Charge Carrier Transport Properties in CdTe Single Crystal

Radiation detectors for medical imaging at room temperature have been developed thanks to the availability of large chlorine-doped cadmium telluride (CdTe:Cl) crystals. Microstructural defects affect the performance of CdTe:Cl radiation detectors. Advanced characterization tools, such as Ion Beam Induced Current (IBIC) measurements and chemical etching on tellurium and cadmium faces were used t...

متن کامل

Comparison of ScintSim1 and Geant4 Monte Carlo simulation codes for optical photon transport in thick segmented scintillator arrays

  Introduction: Arrays of segmented scintillation crystals are useful in megavoltage x-ray imaging detectors for image-guided radiotherapy. Most previous theoretical studies on these detectors have modelled only ionizing-radiation transport. Scintillation light also affects detector performance. ScintSim1, our previously reported optical Monte Carlo code for such detector...

متن کامل

Time-dependent analysis of carrier density and potential energy in spherical centered defect InGaAs/AlGaAs quantum dot (SCDQD)

Interaction and correlation effects in quantum dots play a fundamental role in defining both their equilibrium and transport properties. Numerical methods are commonly employed to study such systems. In this paper we investigate the numerical calculation of quantum transport of electrons in spherical centered defect InGaAs/AlGaAs quantum dot (SCDQD). The simulation is based on the imaginary time...

متن کامل

Time-dependent analysis of carrier density and potential energy in spherical centered defect InGaAs/AlGaAs quantum dot (SCDQD)

Interaction and correlation effects in quantum dots play a fundamental role in defining both their equilibrium and transport properties. Numerical methods are commonly employed to study such systems. In this paper we investigate the numerical calculation of quantum transport of electrons in spherical centered defect InGaAs/AlGaAs quantum dot (SCDQD). The simulation is based on the imaginary time...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2005