Effect of composition and pressure on the nitrogen isoelectronic trap inGaAs1−xPx

The luminescence and absorption behavior of the nitrogen trap in $\mathrm{Ga}{\mathrm{As}}_{1-x}{\mathrm{P}}_x$ is investigated as a function of composition and pressure. Luminescence and absorption data support the identification of strong phonon coupling to the broad $N_x$ band (formerly identified as $\mathrm{NN}$-pair recombination transition for $x\lesssim 0.85$. Pressure measurements in the composition range $0.38\lesssim x\lesssim 0.48$ demonstrate, in a continuous manner, the behavior of the $N_{\Gamma }$ transition (previously identified as $N{N}_3$ for crystal composition $x=0.37\mathrm{} \mathrm{and} 0.38$ and the $A$ line for $0.40\lesssim x\lesssim 0.55$. The oscillator strength of this state for an $x=0.48$ $\mathrm{Ga}{\mathrm{As}}_{1-x}{\mathrm{P}}_x:\mathrm{N}$ sample is observed to decrease with increase in pressure, disappearing at ∼ 6.6 kbar or a simulated composition $x\sim 0.55$ ($E_{\Gamma }-E_N\sim 140$ meV).