Effects of high dose proton irradiation on the electrical performance of ZnO Schottky diodes

Abstract

Bulk ZnO Schottky rectifiers with Pt rectifying contacts were exposed to 40 MeV protons at fluences from 5 × 109 to 5 × 1010 cm–2. These doses correspond to that received in more than 10 or 100 years, respectively, in low earth satellite orbit. The reverse breakdown voltage of the ZnO diodes increased from ∼3.2 V (taken at a current density of 0.1 A/cm2) in unirradiated devices to ∼3.9 V after the highest proton dose. The effective barrier height decreased with proton dose from 0.37 eV to 0.35 eV while the diode ideality factor increased from 1.8 to 1.9 for the 5 × 1010 dose. The very high tolerance of the ZnO diodes to high doses of energetic protons suggests that this material is well‐suited to applications requiring high radiation tolerance. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The effect of high-energy electron irradiation on ZnO-based ohmic and Schottky contacts

“…Also these traps that prevail at the interface can compensate the pre-existing donors at the interface by lowering the N d [9] and dislocates the position of Fermi level with respect to the conduction band (see table 1). In recent years, similar observations have been reported in proton irradiated ZnObased Schottky diodes as well [27,28]. These results may have practical as well as fundamental significance, because the high energetic particles are often encountered in space applications.…”

Thermal stability of CdZnO∕ZnO multi-quantum-wells

“…This has been shown to ensure efficient excitonic optical emission at elevated temperatures up to even 650 K. 3 Additional advantages of ZnO include higher quantum efficiency, greater resistance to highenergy radiation, and better compatibility with wet chemical etching. 1,[4][5][6] A critical element for the development of ZnObased optical devices is the ability to tune its band gap through alloying, leading to the formation of both energy barriers and quantum wells that unlock the route toward more effective quantum confinement and increased internal quantum efficiency. Moreover, the ability to tune the ZnO band gap would enable light emission over a broad spectrum, i.e., from the deep UV to the visible regime, which greatly increases the perspective applications for this material system.…”

Electron-beam-induced current and cathodoluminescence studies of thermally activated increase for carrier diffusion length and lifetime in n-type ZnO

“…Recent technological improvements in ZnO technology prompted vigorous efforts to produce Schottky contacts to ZnO with good rectifying characteristics. [11][12][13][14] Generally, the challenges in this area are related to low breakdown voltage and high leakage current of such contacts. Figure 1 shows the current-voltage ͑I-V͒ characteristics of Au Schottky contacts deposited on the nonpolar a plane of ZnO.…”