Defect study of MOVPE-grown InGaP layers on GaAs

Avoidance of surface-related defects in MOVPE-grown InGaP layers

“…We have previously reported [6] that towards the surface of a lattice-matched InGaP layer grown at 580 1C with a V/ III ratio of 70, a dominant electron trap (labeled E1) about 0.75 eV below the conduction band edge E C is found, if InGaP is not capped with a GaAs layer thicker than 50 nm. Fig.…”

“…The InGaP layer grown with the higher V/III ratio, curve 3, shows a factor of up to five lower trap concentration than the other samples. We showed previously that with the higher V/III input ratio during the InGaP growth, the type of ordering remains unchanged [7] and that a small increase in the ordering degree did not affect the formation of the E1-related defect [6]. Thus the main reason for the lower E1 trap concentration with higher V/III ratio has to be a lower concentration of an intrinsic defect.…”

“…The dominant electron trap (labeled E1) has been correlated to the existence of oxygen in the InGaP layer resulting from indiffusion from the layer surface exposed to air [6]. Additionally, it has been suggested that the initial concentration of the deep-level defect E1 at the surface as well as its diffusion into the InGaP layer at room temperature are apparently promoted by intrinsic defects in the InGaP layer determined by its growth condition.…”

InGaP Solar Cell with InGaP Multiple Quantum Wells Grown under Optimized V/III Ratio

“…Obtaining InGaP crystals with fewer defects is difficult because the crystal growth of the InGaP is relatively complicated due to the differences in the growth parameters between InP and GaP. [17,18] Therefore, carefully controlling crystal growth parameters, such as the V/III ratio, is necessary for the growth of InGaP structures with fewer defective InGaP crystals.…”