Impact of current-induced degradation process on the electro-optical characteristics of InGaN/GaN multiple-quantum-well photodetectors fabricated on sapphire substrate

Abstract

The impact of defects on the degradation behaviors of InGaN/GaN multiple-quantum-well photodetectors submitted to dc current stress has been intensively studied. The root mechanism for degradation has been studied employing combined electro-optical measurements. The collected results indicate that (i) stress can induce an increase in parasitic current leakage paths and trap-assisted tunneling in reverse and subturn-on forward bias ranges, respectively; (ii) during stress, the overall capacitance increases and localization improves in the apparent carrier concentration within the active region; (iii) stress causes a significant decrease in quantum well intensity and an increase in yellow luminescence; (iv) stress induces an increase in the external quantum efficiency due to broadening of the space-charge region; and (v) the detectivity of the device decreases after the stress treatment. These results suggest that degradation is largely attributed to the activation of initially inactive defects, mainly Mg–H, C-related, and VGa defects in the investigated devices, with consequent worsening of their performances.

Tunneling recombination in GaN/InGaN LEDs with a single quantum well

“…Dependence of the reverse current on F 1/2 for the structure under study at room temperature. The dependence of the reverse current on F 1/2 on a logarithmic scale is close to linear, which confirms the validity of the expression used in the work [16]. 212 S. V. Bulyarsky, L. N. Vostretsova, V. A. Ribenek…”

“…By solving kinetic equations (13) corresponding to the proposed model, an expression for the inverse characteristics of the studied structures ( 16) is obtained. According to (16), the reverse current exponentially depends on F (F is the electric field strength), which is confirmed experimentally (Fig. 10).…”

“…In other studies, changes in the characteristics of LED structures during aging are associated with the formation of non-radiative recombination centers in the active region during prolonged current flow. The influence of defects on the degradation characteristics of InGaN/GaN photodetectors with several quantum wells subjected to direct current was investigated [16]. The degradation of electrical and optical characteristics is largely explained by the activation of initially inactive defects, primarily defects associated with Mg-H, C-, and V Ga , in the studied devices, followed by deterioration of their characteristics.…”

Current-induced degradation behaviors of InGaN/GaN multiple quantum well UV photodetectors: Role of electrically active defects

“…Therefore, for the development of highly stable UV-PDs, the role of surface states and high defect density, including threading dislocations (TDs) and native point defects need to be studied rigorously. In our earlier works [15,16], we reported the impact of constant current stress on the different electrical and optical properties of similar PDs and observed that the degradation processes are usually associated to the newly generated electrically active defects in the stressed devices. Based on X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results, Horng et al [4] claimed that in ZnGa2O4-based deep ultra-violet (DUV) photodetectors, the main degradation is affected by the ozone compensation as well as the surface water adsorption.…”

Effects of electrical stress on the characteristics and defect behaviors in GaN-based near-ultraviolet light emitting diodes

“…However, during operation, some reliability problems, such as optical power (OP) decay, have been the bottleneck for the further development of devices. [5][6][7] Therefore, it is essential to study the degradation mechanisms of GaN-based NUV LEDs under electrical stress.…”