Erratum: ‘‘Evidence for field enhanced electron capture by EL2 centers in semi-insulating GaAs and the effect on GaAs radiation detectors’’ [J. Appl. Phys. 75, 7910 (1994)]

Electric field dependent EL2 capture coefficient in semi-insulating GaAs obtained from propagating high field domains

“…1 At room temperature the Fermi level is pinned at the EL2 midgap energy level, which is partially ionized and in equilibrium with electrons in the conduction band via trapping ͑coefficient c n ) and emission ͑rate e n ). If the system is driven out of equilibrium by an external driving force, for instance a large electric field, the electron distribution is no longer described by the Boltzmann statistic 5 and the trapping coefficient and emission rate are modified. In SI GaAs the trapping coefficient is found to increase with electric field, leading to negative differential resistance, 2 which is responsible for noise in devices based on SI GaAs substrates, [3][4][5] low frequency current oscillations and high field domain formation.…”

“…If the system is driven out of equilibrium by an external driving force, for instance a large electric field, the electron distribution is no longer described by the Boltzmann statistic 5 and the trapping coefficient and emission rate are modified. In SI GaAs the trapping coefficient is found to increase with electric field, leading to negative differential resistance, 2 which is responsible for noise in devices based on SI GaAs substrates, [3][4][5] low frequency current oscillations and high field domain formation. [6][7][8] Theoretically the field enhanced trapping is explained both by a configurational barrier of 60 meV due to a multiphonon capture process which requires an electric field of about 0.5 kV/cm to be overcome 9 or by an enhanced capture of hot electrons in the L valley which occurs at about 3.0 kV/cm.…”

Response of semi-insulating thick GaAs detector for -particles, -rays and X-rays

“…Their energy resolution was, however, worse (23.53 keV for 5.486 MeV a-particles and 3.8 keV (3.1%) at 122 keV g-rays) [2]. From this time a new technology of the bulk semi-insulating GaAs has been developed [2][3][4][5][6][7][8][9][10][11][12]. Unfortunately, up to now there are no better results published for a-particles than those reported in Ref.…”

“…Unfortunately, the higher bias voltage could not be applied due to surface sparking in the device. Extrapolating measured points, the 100% CCE was expected at about 700 V bias voltage.The CCE [16][17][18][19] and amplitude [4][5][6] as function of the bias voltage show saturation for higher bias voltages; unfortunately, the maximal bias voltage used was not more than 200 V in these works. The bias voltage up to 1000 V was applied in Ref.…”

“…This method was reported in a few papers describing results from detectors that had full depletion widths of around 100 mm [3][4][5]. Using X-rays measurements the thickness of the detector depletion layer was estimated to be about 200 mm [6]. The aim of this work was to investigate the response of the detectors based on semi-insulating GaAs for a-particles, X-rays and low-energy g-rays.…”