16 research outputs found
Electronic properties of shallow level defects in ZnO grown by pulsed laser deposition
We have used deep level transient spectroscopy (DLTS) to characterise four defects
with shallow levels in ZnO grown by pulsed laser deposition (PLD). These defects all have
DLTS peaks below 100 K. From DLTS measurements and Arrhenius plots we have calculated
the energy levels of these defects as 31 meV, 64 meV, 100 meV and 140 meV, respectively,
below the conduction band. The 100 meV defect displayed metastable behaviour: Annealing
under reverse bias at temperatures of above 130 K introduced it while annealing under zero
bias above 110 K removed it. The 64 meV and 140 meV defects exhibited a strong electric
field assisted emission, indicating that they may be donors
Electronic properties of shallow level defects in ZnO grown by pulsed laser deposition
We have used deep level transient spectroscopy (DLTS) to characterise four defects
with shallow levels in ZnO grown by pulsed laser deposition (PLD). These defects all have
DLTS peaks below 100 K. From DLTS measurements and Arrhenius plots we have calculated
the energy levels of these defects as 31 meV, 64 meV, 100 meV and 140 meV, respectively,
below the conduction band. The 100 meV defect displayed metastable behaviour: Annealing
under reverse bias at temperatures of above 130 K introduced it while annealing under zero
bias above 110 K removed it. The 64 meV and 140 meV defects exhibited a strong electric
field assisted emission, indicating that they may be donors
Shallow Donors and Compensation in Homoepitaxial ZnO Thin Films
Nominally undoped homoepitaxial ZnO thin films grown with pulsed-laser deposition at various oxygen partial pressures (3 x 10(-4)-0.1 mbar) were investigated with respect to shallow donors and compensation. From x-ray diffraction and photoluminescence studies, a correlation of the oxygen partial pressure and the strain in the samples was found. Capacitance-voltage and thermal admittance measurements, using PtO (x) -Schottky diodes, revealed a higher compensation for increasing oxygen partial pressure. A shallow donor level with a thermal activation energy of similar to 40 meV was observed by thermal admittance spectroscopy. This defect level was attributed to the I(3a) transition observed in photoluminescence and commonly assigned to interstitial zinc.</p
Shallow Donors and Compensation in Homoepitaxial ZnO Thin Films
Nominally undoped homoepitaxial ZnO thin films grown with pulsed-laser deposition at various oxygen partial pressures (3 x 10(-4)-0.1 mbar) were investigated with respect to shallow donors and compensation. From x-ray diffraction and photoluminescence studies, a correlation of the oxygen partial pressure and the strain in the samples was found. Capacitance-voltage and thermal admittance measurements, using PtO (x) -Schottky diodes, revealed a higher compensation for increasing oxygen partial pressure. A shallow donor level with a thermal activation energy of similar to 40 meV was observed by thermal admittance spectroscopy. This defect level was attributed to the I(3a) transition observed in photoluminescence and commonly assigned to interstitial zinc.</p
Electronic properties of shallow level defects in ZnO grown by pulsed laser deposition
We have used deep level transient spectroscopy (DLTS) to characterise four defects
with shallow levels in ZnO grown by pulsed laser deposition (PLD). These defects all have
DLTS peaks below 100 K. From DLTS measurements and Arrhenius plots we have calculated
the energy levels of these defects as 31 meV, 64 meV, 100 meV and 140 meV, respectively,
below the conduction band. The 100 meV defect displayed metastable behaviour: Annealing
under reverse bias at temperatures of above 130 K introduced it while annealing under zero
bias above 110 K removed it. The 64 meV and 140 meV defects exhibited a strong electric
field assisted emission, indicating that they may be donors
Electronic properties of shallow level defects in ZnO grown by pulsed laser deposition
We have used deep level transient spectroscopy (DLTS) to characterise four defects
with shallow levels in ZnO grown by pulsed laser deposition (PLD). These defects all have
DLTS peaks below 100 K. From DLTS measurements and Arrhenius plots we have calculated
the energy levels of these defects as 31 meV, 64 meV, 100 meV and 140 meV, respectively,
below the conduction band. The 100 meV defect displayed metastable behaviour: Annealing
under reverse bias at temperatures of above 130 K introduced it while annealing under zero
bias above 110 K removed it. The 64 meV and 140 meV defects exhibited a strong electric
field assisted emission, indicating that they may be donors
Electronic properties of shallow level defects in ZnO grown by pulsed laser deposition
We have used deep level transient spectroscopy (DLTS) to characterise four defects
with shallow levels in ZnO grown by pulsed laser deposition (PLD). These defects all have
DLTS peaks below 100 K. From DLTS measurements and Arrhenius plots we have calculated
the energy levels of these defects as 31 meV, 64 meV, 100 meV and 140 meV, respectively,
below the conduction band. The 100 meV defect displayed metastable behaviour: Annealing
under reverse bias at temperatures of above 130 K introduced it while annealing under zero
bias above 110 K removed it. The 64 meV and 140 meV defects exhibited a strong electric
field assisted emission, indicating that they may be donors
Electronic properties of shallow level defects in ZnO grown by pulsed laser deposition
We have used deep level transient spectroscopy (DLTS) to characterise four defects
with shallow levels in ZnO grown by pulsed laser deposition (PLD). These defects all have
DLTS peaks below 100 K. From DLTS measurements and Arrhenius plots we have calculated
the energy levels of these defects as 31 meV, 64 meV, 100 meV and 140 meV, respectively,
below the conduction band. The 100 meV defect displayed metastable behaviour: Annealing
under reverse bias at temperatures of above 130 K introduced it while annealing under zero
bias above 110 K removed it. The 64 meV and 140 meV defects exhibited a strong electric
field assisted emission, indicating that they may be donors