Annealing in GaInNAs system

Abstract

The effect of post-growth thermal annealing on crystallinity and bandgap in GaInNAs systems is systematically investigated. Annealing greatly improves the crystallinity of GaInNAs and also blue shifts the bandgap. This improved crystallinity is due to the elimination of non-radiative centres, and is not directly related to the blue shift in the bandgap. The blue shift may be closely related to the red shift in the bandgap seen when N is added to GaInNAs; if so, this would provide a clue to the reasons for the red shift in the bandgap of III-N-V alloys. The unexpected behaviour of the bandgap in GaInNAs is investigated by examining the bonds through optical phonons. We have found that the bandgap varies with the strength or length of the GaN bonds in GaInNAs. Annealing changes atomic positions in a unit cell of GaInNAs and thus blue shifts its bandgap.

Characterization of InGaAsSbN layers grown on InP by MBE

“…In addition, a blue-shift of the PL peak energy was observed by the annealing. Such a blue-shift was generally observed for InGaAsN layers on GaAs [9]. The results for the InGaAsSbN layer on InP shown in Fig.…”

“…It is known that the PL intensity increases with increasing annealing temperature up to 700 °C. The increase in the PL intensity is due to the decrease of defects induced by nitrogen atoms, which act as non-radiative recombination centers [9]. In addition, a blue-shift of the PL peak energy was observed by the annealing.…”

Improved Optoelectronic Properties of Rapid Thermally Annealed Dilute Nitride GaInNAs Photodetectors

“…6 Many material quality and device performance issues that plagued the early development of Ga(In)NAs, such as poor photoluminescence (PL) efficiency, 7 high dark currents, 8 and short minority carrier diffusion lengths, 9 still persist today. In situ or postgrowth thermal annealing is often required to improve the crystal quality of GaInNAs and is widely reported to improve its optical characteristics such as PL intensity and spectral linewidth, although most of the work has focused on thin layers with N composition less than 3% for quantum well lasers, [10][11][12][13][14] with the exception of a recent work on solar cells. 15 It was reported in our previous work that GaInNAs p-i-n diodes lattice matched to GaAs with low background doping concentration, low dark currents, and a photoresponse cutoff wavelength up to 1.28 lm could be achieved without postgrowth annealing.…”

Reduction of dark current and unintentional background doping in InGaAsN photodetectors by ex situ annealing

“…Consequently, its use in the laser, photodetector and solar cell applications has been plagued by poor material characteristics such as poor photoluminescence (PL) 3 , high dark currents 4 , and short minority carrier diffusion lengths 5 . Postgrowth annealing is often required to improve the crystal quality of Ga 1-x In x N y As 1-y and is widely reported to increase the PL intensity, reduce its spectral linewidth and cause a blueshift of the PL peak, though most of the work has focused on Ga 1-x In x N y As 1-y quantum well structures [6][7][8][9] .…”