Influence of deformation on the luminescence of GaN epitaxial films

Abstract

The effect of indentation on the cathodoluminescence (CL) of GaN:Si epitaxial films has been investigated in the scanning electron microscope. Deformation produces changes in the defect structure which are monitored through the changes induced in the cathodoluminescent emission. Besides a general quenching of the luminescence, an increase of the relative intensity of the deep level bands is observed. The effect of different annealing treatments on the CL emission has been investigated.

Cathodoluminescence study of plastically deformed bulk ZnO single crystal

“…These two fundamental features have been observed previously for ZnO using a spherical indenter [11]. This is contrary to GaN, a structurally similar material, where the quenching of luminescence is not extended beyond the indenter contact diameter [8,[12][13][14]. The intensity of the near gap CL emission is drastically suppressed after indentation because of induced defects (dislocations).…”

“…In spite of the plastic deformation in some materials enhancing the emission in some spectral emission regions as the 550 nm band emission in plastically deformed GaN, the indentation-induced defects (e.g. dislocations) acting as efficient nonradiative recombination centers result in a drastic diminution of the intensity of another band emission such as 360 nm band emission in GaN [8]. This is a non-desirable effect for devices that work in that spectral region.…”

Berkovich indentation-induced deformation behaviors of GaN thin films observed using cathodoluminescence and cross-sectional transmission electron microscopy

“…According to the previous studies [7][8][9][10][11][12][13][14][15][16], we note here that the critically applied indentation load for direct identification of the multiple ''pop-in'' events in P-h curve is not only dependent on the type of indenters used, but also very much dependent on the test systems and the maximum indentation loads applied. Consequently, we reasonably deduce that these discrepancies are mainly owing to the various indentation methods used.…”

“…In addition, the intensity of the near-gap CL emission from GaN thin films is dramatically suppressed after Berkovich nanoindentation because of induced defects/dislocations. Despite the star-of-David-like rosettes have been investigated around the larger-loading indentations [15,16]; however, such details could not be clearly resolved for the lower indentation loading in our present work.…”

Indentation of GaN: A Study of the Optical Activity and Strain State of Extended Defects

“…Zaldivar et al [1] investigated the luminescence properties of extended defects induced by microindentation of GaN epitaxial films by cathodoluminescence (CL), in particular the evolution of deep-level defects in connection with the appearance of dark lines in the CL image. More recently, Kucheyev et al [2] reported on the deformation behavior of GaN by nanoindentation.…”